Photonics News

VOLUME 10 ISSUE 01 FEBRUARY 2008

ANNUAL PHOTONICS WORKSHOP 2007 Inside this issue: In brief... The Annual Photonics His lecture was followed Workshop (APW- 2007) was by a lecture on From the editors desk 2 held during 27-28 February “Fluorescence Tech- 2007. The focal theme of the niques to probe New VC for CUSAT 2 Workshop was “Recent Trends Photonic Materials” by From ISP labs 3 in Nonlinear Optics”. The Prof. V Ramakrishnan Work shop was inaugurated by from Madurai Kamaraj Alumni column 6 the Vice Chancellor Dr. P K University. Prof. K Abdul Azis. About 40 partici- Porsezian from the Invited article 7 pants from various parts of the Pondicherry University We hear that…. 8 country participated in the spoke on “Nonlinear programme. Prof. V P N Nam- Properties of Optical Sound success 11 poori spoke on “Nonlinear Fibre”. “Fundamentals Lighting the innovation… optics and optical computing”. of Nonlinear Optics” Inaugural session of APW 2007 ISP-SPIE student 12 was introduced by Dr. N chapter column V Unnikrishnan, “Cavity QED”, and Dr. K G K War- rier from R.R.L, Thiruvananthapu- In the lime light 13 M.G.University. On the second day ram on “Mesoporous silica aerogels”. Recent publications 14 there were four lectures. In the evening the Science Day Lecture Commodore Nambiar of was delivered by Prof. V Unnikrish- Picture parlare 15 Indian Navy (retd.) gave nan Nair, Dean Faculty of Science, a lecture on “Lasers and CUSAT. There was one session for

Applications”, Dr. T poster presentation. The event came Ramesh Babu, Physics to a close with Karnatic musical pro- Release of photonics news 07. Dept., CUSAT on gram and other cultural activities. Distinguished visitor

Dr. Sajeev John , Department of properties and applications”. He is Physics , University of Toronto, the current holder of the C. V. Raman Canada. Raman Chair Professor. Chair Professorship of the Indian Academy of Sciences. as "photonic crystals". The Prof. Sajeev John delivered a ⇒ Released in basic concept was developed special lecture on “Photonic Band association with: in a series of papers by Pro- Gap Materials – Semiconductors of fessor John during 1980's. Dr. th Centre of Excellence Light” on 29 October 2007. The lec- Professor Sajeev Sajeev is the winner of the Insti- in About Lasers this and bulle- ture was sponsored by SPIE, The In- John is one of the world's Optoelectronic “engineering of ternational Society for Optical Engi- leading Condensed Matter the fundamen- Sciences, Photonics neering. Physicists whose work on tal properties of Society of India, electro mag- Photonic Band Gap (PBG) Localization of Light in ISP-SPIE student netic waves” materials are artificial, periodic, di- Random media similar to chapter & ISP-OSA electrics that enable engineering of the Anderson Localization of student chapter. tute of Electrical and Elec- most fundamental properties of elec- electrons has led to what is tronics Engineers (IEEE) tromagnetic waves. PBG materials known as Semi Conductors ⇒ For private LEOS International Quantum are of great practical importance for of Light or Photonic Band circulation only. Electronics Award in 2007 for all-optical communications, informa- Gap Materials. His name is “the invention and develop- tion processing, and the use of lasers synonymous with the field ment of light- trapping crys- in clinical medicine. that has come to be known tals and elucidation of their

Cochin University of Science And Technology, Kochi, Kerala FROM THE EDITOR’S DESK

. The year that was 2007.. The year two thou- five year integrated M.Sc. sor Lakshmanan, Professor sand seven was a period of (Photonics) students came Thanu Padmanabhan , Dr. hectic activities as far as out in July 2007. More than Rajaram Nithyananda and International School of ninety percent of the stu- Dr. Reji Philip covering Photonics and Centre of dents who have success- wide spectrum of topics Excellence in Lasers and fully completed the course like Astrophysics , Photonic Optoelectronics Sciences have joined prestigious in- crystals and Adaptive Op- were considered. At the stitutions for research in tics. outset let us welcome Dr. India and abroad. Some of The present issue of Gangan Prathap, who took them preferred research Photonics News is a chroni- charge as the Vice Chancel- programme over place- cle of various activities lor of Cochin University of ments in industries. Let us which took place in ISP and Science and Technology on congratulate the future CELOS. We take this op- 4th February 2008. Dr. photonians and wish them portunity to congratulate Prathap, a specialist in bright future. Mr. Jinesh Mathew whose Aerospace Engineering, is ISP and CELOS paper on humidity sensor a Bhatnagar Award Winner jointly with ISP-SPIE and figured in one of the most and has excellent academic ISP-OSA Student Chapters downloaded. achievements. Under the organized several pro- Let us thank all leadership of the new Vice gramme during 2007 and those who worked silently Chancellor, CUSAT will get they should be proud of behind the curtain to bring evolved into one among the arranging special lectures ISP and CELOS to the fore- top institutions of the by distinguished visitors front of the academic ac- angels are debating the best way to use it” ~Alan Valentine world. like Professor Ghatak , Pro- tivities in CUSAT. “Whenever science makes a discovery, the devil grabs it while The first batch of fessor Sajeev John , Profes-

New Vice Chancellor for CUSAT

04/2008. Dr. Prathap was which was published from formerly scientist-in-charge, Holland. He is also mem- CSIR Centre for Mathemati- ber of the editorial boards cal Modelling and Com- of many scientific journals. puter Simulation, Banga- Dr. Prathap completed his lore. A winner of Bhatnagar schooling in Singapore and Award in 1990, Dr. Prathap took his B.Tech, in Aero- Editor-in-Chief belongs to Mayyanad in space Engineering with first Dr.Gangan Prathap Kollam. Sociologist Latha rank from IIT Madras in V. P. N. NAMPOORI Dr Gangan Prathap is the Sukumaran is his wife and 1974. He took his doctorate new Vice Chancellor of CU- their son Rahul is an engi- from IIT Madras in 1978. Editors SAT. Dr Gangan Prathap, a neer with L&T, Baroda. He was accorded fellow- renowned scientist, took Dr. Pratap has pub- ships by various research over as the new Vice- lished more than 300 re- institutions like Jawaharlal MATHEW . S Chancellor of the Cochin search papers, including the Nehru Centre for Advanced SREELEKHA . G University of Science and book “Finite Element in Scientific Research and In- Technology on February Structural Mechanics,” dian Academy of Science. SUDEESH . K

page 2 photonics news 2008 Volume 10, Issue 01 from ISP labs

Dyes modify thermal properties of clay The thermal dif- samples are also experi- evaluated by knowing the fusivity (TD) measure- mentally obtained. The transition frequency be- ments of montmorillonite sintered samples show a tween the thermally thin clays intercalated with the higher TD though they to thermally thick region cationic dyes like methyl- show similar trend as un- from the log–log plot of ene blue, malachite green sintered pellets. A varia- photo acoustic amplitude and auramine O, which tion in dye concentration versus chopping fre- are commonly used in the and sintering temperature quency. Analysis of the Photothermal process. textile industry, are car- can be used for tuning the data was carried out on ried out using photoacous- TD value of the clay to the the basis of the one- tic technique. The TD of desired level. (NHTEP dimensional model of dye adsorbed clays is ob- 2007 India, NLS-2007). The Rosencwaig and Gersho. served to change with laser induced non- The present investigation “The TD of variation in dye concentra- destructive photo acoustic reveals that amount of tion. The repeatedly ad- technique has been em- monomer has great influ- dye adsorbed sorbed samples show a ployed to measure the ence on the propagation of clays is lesser TD than the single thermal diffusivity of den- heat carriers and hence on adsorbed samples. The tal resin. The thermal the thermal diffusivity observed to TD values of the sintered diffusivity value was value. (ICIAS 2007, Malay- sia). change with variation in dye Raman study of polymer optic fibers concentration” Polymethyl methacry- length of the optical fibre its characterisation are being late (PMMA) optical fibres are is studied. Investigations studied . fabricated by preform drawing are carried out on the process. The Raman spectra of variation of FWHM of PMMA fibers are recorded us- Raman peak at 2957 cm-1 Polymer ing a diode pumped solid state with the length of the optical laser 532 nm and a CCD- optical fibre and at differ- fibre Spectrograph in the 400-3800 ent pump powers. The cm-1 range. The variation of the Fabrication of nanosilver Raman intensity with the doped polymer fibres and

Laser Produced Plasma The laser induced ize the electrical signals formation by Laser Blow Off of breakdown study (LIBS) of generated by planar tar- thin flms under magnetic fields materials in transverse mag- gets forming plasma is using multiple diagnostics, in- netic fields and their emission also found to be suitable cluding ICCD imaging. Efforts behavior was the focal study of for studying plasma dy- have been made to reconstruct Image captured using ICCD our laser plasma group. Neu- namics in magnetic field. the emmissivity profiles of plas- tral species in plasma show a Presently, the mas interior through topog- strange response with splitting studies are being extended raphic techniques (pixel in the field and such multiple to a collaborative level and method). Digital interferomet- structures throw light into are being pursued at the ric method used in our lab for some of the complex process LD group of IPR, the in situ monitoring of the taking place in plasma. Our Ahamedabad. We have radial density profiles of plas- newly adopted probe based extended the investigation mas as also needs special men- Li target film used for technique to successfully util- to the forward plasma tion. forward plasma genera- tion

photonics news 2008 page3 from ISP labs

Up conversion lasing process in polymer optical fiber

Two photon ex- ment of an up conversion achieved by mixing differ- cited fluorescence studies polymer fiber laser which ent ratios of the dyes. The in Rh6G, Rh B and Rh6G- can be tunable over a dye doped POF amplifier Rh B dye mixture doped broader wavelength re- (POFA) is pumped axially POF is carried out in our gion. Rhodamine 6G and using 532 nm, 10ns laser lab using 800nm, 80 fs rhodamine B dye mixture pulses from a frequency laser beam from a mode- doped polymer optical doubled Q-switched Nd: locked Ti: Sapphire laser fiber (POF) amplifier YAG laser and the signals ‘Tsunami’. The studies which can operate in a are taken from an optical illustrate that the combina- broad wavelength region parametric oscillator Energy transfer in Rh 6G tion of a well designed (60nm) has been success- (OPO). A maximum gain doped fibre mixtures of organic chro- fully fabricated and tested. of 22 dB at 617nm wave- mophores incorporated Tunable operation of the length has been obtained into a fiber geometry is amplifier over a broad for a 7cm long dye mix- appealing for the develop- wavelength region is ture doped POFA.

Synchronization in Chaotic systems: “Rhodamine 6G and

rhodamine B dye Different routes to synchronization have rameter mismatch is stud- mixture doped polymer been established in vari- ied. The effect of delayed feedback on the dynamics optical fiber (POF) ous chaotic systems. Tran- sition from phase to com- of a single Nd:YAG laser amplifier which can plete synchronization and also on a coupled sys- tem is also under investi- operate in a broad through lag synchroniza- tion in coupled chaotic gation wavelength region Nd:YAG lasers with a pa- (60nm) has been Lorenz attractor successfully fabricated and tested” Laser induced fluorescence based optical fiber probe for analyzing bacteria

Laser induced fluo- niques to characterize bio- species of bacteria, a Gram- rescence has been shown to logical samples. Usually, positive bacteria namely Ba- be a very sensitive analytical fluorescing dyes are also cillus smithii, and Vibrio algi- tool for biological studies. chosen for LIF based stud- nolyticus, a Gramnegative There are lots of applications ies apart from the fluoro- bacteria. The fiber sensor was using LIF technique. The phores present in the cells clearly able to distinguish quantum efficiency of fluoro- or tissues. between the two species of phores can change as a func- Optical fiber has bacteria. tion of variations in the local been utilized effectively in Quenching effect of environment of the fluoro- various LIF based studies the dye Rhodamine B by Ba- phore molecule like viscosity, Optical fiber based laser cillus smithii was observed. An optical fiber based ar- temperature, refractive in- induced fluorescence (LIF) The effect of dye on the sam- rangement as a sensor element dex, etc. Measuring fluores- measurements were car- ples was also studied in de- cence quantum efficiency is ried out using Rhodamine tail. one of the experimental tech- B to analyze two different

page 4 photonics news 2008 Volume 10, Issue 01 from ISP labs

Design and fabrication of Photoplethysmograph

A high sensitiv- sions and power con- pulse (P0) and the systolic ity, low power, low cost sumption. The probe can peak (P1) demonstrated sensor has been developed be well tolerated by the strong correlations with for sensing the blood vol- subject and is self con- age. The younger age ume pulse using transmis- tained and portable Work group had lower MRT, S.I,

sion mode photoplethys- has also been carried out and P0/P1 values when PPG measurement taken at mography (PPG) from the to study noninvasively the compared to the older ISP finger tip. A heart rate systolic and diastolic char- group. This study estab- meter was designed with a acteristics of the resting lishes the usefulness of the PIC as its heart. For heart peripheral volume pulse blood volume pulse con- “A heart rate rate (HR) estimate com- using a normalized mean tour analysis in determin- meter was parison, PPG signals are pulse as a function of age ing the changes in the elas- designed with a evaluated by comparing using an indigenously tic properties of the vascu- their beat-to-beat estimates developed hardware lar system with age. The PIC as its heart. with the corresponding R- setup. Evaluation of the study of the relationship For heart rate (HR) R intervals from an elec- minimum rise time (MRT), between the blood vol- estimate trocardiogram (ECG). The Stiffness index (S.I) and ume pulse signals and main advantages of the the ratio between the blood pressure is currently comparison, PPG proposed approach are the pulse height at the dicrotic under progress signals are reduction in cost, dimen- notch of the blood volume evaluated by comparing their beat-to-beat estimates with the corresponding R-R Fluorescence spectroscopy of nano colloids of ZnO intervals from an Fluorescence length and there is a red shift in emission process in these electrocardiogram spectra of ZnO consist of peak with excitation wavelength. This ob- media. In es- two principal bands: UV servation has been attributed to the pres- s e n c e , t h e (ECG)“ and visible. Apart from ence of energetically different associated inefficient en- the known band gap 380 forms of the constituent molecules and ergy transfer nm and impurity 530 nm slow rate of the excited state relaxation between the emissions, emissions at upper and the 420 and 490 nm are de- 1.2 lower vibra- Excitation Wavelength veloped with particle size. a 230 nm tional levels of 346 370 1.0 383 434 b 275 nm The blue luminescence in c 325 nm the excited state ZnO is by the mechanism d 355 nm of these particles 0.8 of the transition from near owing to short fluorescence band edge to deep accep- 0.6 d tor level and the green a b c lifetime is pri- luminescence is by the 0.4 marily responsi- mechanism of the transi- ble for the exci- tion from deep donor level 0.2 tation wave- SEM of ZnO Nano colloids

Normalized Fluorescence Intensity (a.u) Intensity Fluorescence Normalized length depend- to valence band. The fluo- 0.0 rescence behaviour of 350 400 450 500 ent spectral shift nano colloids of ZnO has Wavelength (nm) of ZnO nano been studied as a function colloids. of the excitation wave- Fluorescence shift of ZnO nano particles

photonics news 2008 page5 alumni column

Optofluidics – Marriage of light with fluids

Quest for mally in a changing envi- ality. However, progres- miniaturized devices ronment sion can be made on fur- using photonic industry The potential ther integration of sophis-

and fundamental prop- applications of optofluidic ticated nano/micro fluidic erties of fluids has cre- devices are twofold. In the platforms and fluid actua- Dr. Sajan D George ated a new path of sci- context of integrated bio- tion techniques. Further Scientist, Institut für chemical sensing, fluidics Nano- und entific research, popu- employment of liquid Mikroprozesstechnik, larly now known as can be used to carry sub- crystals and nonlinear Leibniz Universität Optofluidics. Optoflu- stances to be analyzed fluids will enable dynami-

Hannover, Callinstraße 36, idics fundamentally through highly sensitive cally configurable D 30167, Hannover, aims at manipulating micro photonic circuits. photonic devices with Germany E mail: [email protected] hannover.de

A schematic diagram that summarizes our ap- proach is shown above, where a nanostructured optical substrate is integrated with a microfluidic structure that performs functions such as recon- figuration of functionality, adaptation of proper- “In the context of ties, distribution of chemicals to be analyzed, and integrated bio- temperature stabilization chemical sensing, fluidics can be used to carry substances

to be analyzed fluids and light at the Conversely, microfluidics wide range of applica- through highly microscale and exploit- can be exploited to control tions. Surface chemistry ing their interaction to microphotonic devices, modulation of fluidics also sensitive micro create highly versatile making them tunable, can be used to manipulate photonic circuits“ systems, ranging from reconfigurable and adap- the properties of system. optical lenses to opto- tive.Current investigation In short, optofluidics offer fluidic microscopes. The into optofluidic intergra- a new area of research introduction of liquids in tion is still in very forma- which can potentially re- the optical structure en- tive stage. Most research sult in low cost diagnosing ables flexible fine-tuning thus far has approached devices and analytical tool and even reconfiguration optofluidics from stand- with perfect marriage of of circuits such that they point of enhancing may perform tasks opti- light and fluids. photonic device function-

details @ http://www.optofluidics.caltech.edu/optofluidics/index.html

page 6 photonics news 2008 Volume 10, Issue 01 invited article

Optical wave mimicking of coherent population transfer in multilevel atomic systems Quantum–classical populating the middle one. But the extension of STIRAP to a analogies provide useful multilevel system (i.e. an array of waveguides) is a nontrivial insights into basic physical task owing to the non-existence of a dark state with no popu- phenomena that play a fun- lations in all the intermediate levels (i.e. waveguides). Hence damental role in as diverse on a theoretical basis, explained as dressed state approach, physical fields as quantum the transfer process may be basically reduced to a three level computing, nano- STIRAP scheme (straddle STIRAP). It can be shown that a engineering and the search complete population transfer from the level lL› to level lR›, of new techniques to ma- without appreciably populating all the intermediate states, is nipulate and control light possible by a counterintuitive sequence of pump and Stokes Toney Teddy Fernandez waves in photonic struc- pulses, provided that the Rabi frequency W0 is strong tures. The present intertwin- Research student, under ing of apparently unrelated the guidance of Dr. fields is as a result of this new engineering. Optical N.V.Unnikrishnan, analogues of quantum ef- Reader ,School of Pure fects like Bloch oscillations, Zener tunnelling, dynamic and Applied Physics, localization, coherent en- MG University. hancement and destruction of tunnelling, adiabatic sta- bilisation of atoms in strong Currently in a fields etc were successfully Light transfer via a dressed state in the waveguide array with N=3 investigated in engineered and N=5 with input excitation of waveguide L (a) Direct visualisa- collaborative work at tion (b) BEAMprop simulation (c) Coupled-mode equation analysis. photonic systems. These Dipartimento di Fisica studies not only give a new insight into the correspond- enough and the numbers of intermediate levels N is odd. and Istituto di Fotonica The studies were conducted using arrays corre- ing quantum phenomena, e Nanotecnologie del enabling a direct access to sponding to N=3 and N=5 intermediate waveguides. Using the wave packet dynamics, the coupled mode equations via a dressed state approach CNR, Politecnico di yielding but open new ways to ma- Milano, Milano, Italy. nipulate the flow of light iα =−Ω c −Ω c ,ic =−Ω α,ic =−Ωα drawing concepts and meth- & p L s &R &L P &R s ods from the quantum phys- Where WP and WS are the Rabi frequencies of the pump ics context. pulse and the Stokes pulse and cL, cR are the mode ampli- The recent report is tudes of left, right waveguides respectively. based on the optical ana- The waveguide structures were fabricated in an “Optical analogues erbium-doped phosphate substrate using an ion exchange logue of Stimulated Raman of quantum effects Adiabatic Passage (STIRAP), technique carefully designed to satisfy adiabatic evolution of via dressed states in optical the system in its dark state as well as small excitation of all were successfully out-of-resonance dressed states. The dark state is given by waveguide arrays. Prof. investigated in Stefano Longhi, Dr.G.Della Ω − Ω p Valle, Prof. Paola Laporta et s engineered c L = ,α = 0, c R = al. have earlier demon- 2 2 2 2 Ω s + Ω p Ω s + Ω p photonic systems” strated the analogue of Co- herent Tunnelling by Adia- In the experiment, light transfer among coupled batic Passage (CTAP) in a waveguides were visualized using a fluorescence imaging triplet of tunneling coupled technique. An almost complete light transfer from the left to optical waveguides in which the right waveguides is observed for both N=3 and N=5 in- light waves tunnels from the termediate waveguide, in good agreement with the light first waveguide to the last pattern evolution predicted by the numerical simulations one without appreciably using BeamPROP5.0 and coupled mode equations. (APL 92, 011106(2008))

photonics news 2008 page 7 we hear that...

High-brightness LEDs offer energy-efficient lighting solutions

The efficacy of that emits light was only use higher currents (e.g., white LEDs—defined as 0.3 x 0.3 mm and was >350 mA), and that has lumens out divided by nominally used with a required changes to the wall plug watts in—has maximum current of 20 thermal design of both the already surpassed that of milliamps. Larger sizes die and the LED package. incandescent technology and higher currents were Some packages can handle and is now about the same not typically used because currents greater than 1 A the T 1-3/4 package used for a 1 x 1 mm die. The A brightness of technology? as fluorescent lamp tech- nology. One of the most leads that were not able to increase in the die size and common LED packages handle the higher thermal the increase in LED effi- was the T 1-3/4 thru-hole load. ciency have both contrib- package (above left). The To provide more uted to the improvement 1-3/4 designates the pack- light, the size of the light in LED package output. age diameter in eighths of emitting die was in- Researchers at Lamina an inch, so the lens has an creased, with a 1 x 1 mm demonstrated a 28,000- outside diameter of die becoming a fairly com- lumen solid-state white roughly 5 mm. The die mon size. These larger die light engine

“To provide more Zinc oxide nano lasers stand out Researchers in Ger- the laser excitation down range up to room temperature. The light, the size of many have fabricated nano to a spot size smaller than uniform size of the nano rods is the light emitting rods made from zinc oxide 1 µm, the researchers crucial for nanolaser applications, that have been shown to emit found that even single since the ability of the rods to lase die was increased, laser light. Arrays of well or- nanorods standing on a depends strongly on the rod ge- with a 1 x 1 mm dered, vertically aligned zinc substrate could lase. ometry. oxide nanorods have been Zinc oxide (ZnO) die becoming a shown by scientists at the is a wide bandgap semi- fairly common University of Karlsruhe to conductor that emits laser emit laser light. By focusing light in the ultraviolet size”

Mosquito legs show how to walk on water

Researchers at Da- fatigans species have seven into water at a slow constant rate lian University of Technology sections, each covered by a and at different entry angles. in China and Simon Fraser large number of teardrop- Chen Wei Wu and coworkers University in Canada have shaped scales about 15 µm determined that a mosquito can characterized the microstruc- wide and 50 µm long. Ten support 23 times its body weight ture of mosquito legs. They ridges 200–250 nm thick on the surface of water. The con- have found that the insect's extend longitudinally tact angle of a water droplet on a ability to alight on water and along the scales and are mosquito leg is 153°, indicating solid surfaces is intimately connected by numerous that the scales are relatively hy- related to the anatomy of fine transverse ribs. drophobic. They explain that the Nothing but mosquito legs! their legs. The researchers mosquito is able to adjust the Using scanning elec- measured the force a mos- angle and contact length with the tron microscopy, the team quito leg could support on water surface to optimize its discovered that the legs of the surface of water by floatation, which arises from Culex quinquefasciatus and C. plunging legs attached to a surface tension. force-extension apparatus

page 8 photonics news 2008 Volume 10, Issue 01 we hear that...

Femtosecond pulses kill viruses, leave human cells alone

Kong-Thon Tsen killing system using a spiked saline solution with and his collaborators used commercially available known concentrations of an off-the-shelf femtosec- femtosecond laser. A virus, and then irradiated ond laser in this experi- Ti:sapphire laser produces the samples. The treatment mental setup to inactivate 80 fs pulses at a wave- reduced the amount of live viruses in liquid. The tech- length of 850 nm and a virus in the sample by 100- nique offers a means to repetition rate of 80 MHz. to 1000-fold. They found a cleanse microbes from The beam passes through steep dropoff in surviving infected blood. Shaw-Wei a frequency-doubler and viruses at an excitation- Tsen, a biology student at gets converted to violet laser power density of Johns Hopkins University (425 nm) light in pulses greater than 50 MW. It is (Baltimore, MD), and his with a duration of 100 fs the first time that low- father, Kon-Thon Tsen, a and a spectral width of power lasers have been laser expert at Arizona about 60 cm-1. A lens fo- shown to inactivate vi- State University (Tempe, cuses the light beam onto ruses. AZ).developed a virus- the virus sample. They “These nanofibers are so small that

they are less Lighting the nanoworld with nanolamps than the To help light up the light they emit. Appar- nanolamps can last. nanoworld, a Cornell in- ently, these nanofibers are The fibers, made wavelength of terdisciplinary team of easy to produce. But be- of a compound based on the light they researchers has produced fore they can be integrated the metallic element ruthe- microscopic "nanolamps" - into our increasingly nium, are so small that emit” - light-emitting nanofibers smaller electronic devices, they are less than the about the size of a virus or there still is a need to wavelength of the light the tiniest of bacte- know how long these they emit. Such a localized ria.Using a technique light source could prove called electrospinning, the beneficial in applications researchers spun the fibers ranging from sensing to from a metallic element, microscopy to flat-panel the ruthenium, and a poly- displays. mer. These nanofibers are so small that they are less An illustrated closeup of an electrospun fiber. During ex- than the wavelength of the perimentation the organic devices gave off an orange glow

Optical lattice beats atomic-clock accuracy of this light is just like the ticking der, is based on thousands Researchers in the US of a clock — the first neutral- of strontium atoms that Optical clock have built a new optical clock atom timekeeper to be more ac- are trapped in an "optical from strontium atoms that they curate than the standard cesium- lattice" made from over- claim is the world’s most accu- fountain atomic clock. The team lapping infrared laser rate clock to use neutral atoms. determined the clock's accuracy beams. The atoms are According to the team, the time by sending its time signal via a bathed in light from a piece is accurate to about one 3.5-km underground optical fiber separate red laser at a fre- part in 1016 and would neither from JILA to the National Insti- quency corresponding to gain nor lose a second in more tute of Standards and Technol- an atomic transition in than 200 million years. The ogy (NIST) in Boulder, where the strontium — which causes clock, which was built by Jun Ye signal was compared to that from this light to lock into the and colleagues at JILA and the an optical clock based on neutral precise frequency of the University of Colorado in Boul- calcium atoms. transition. The oscillation

photonics news 2008 page9 we hear that...

Trapped rainbow storage of light in metamaterials Recent research has propagation, such as nega- the waveguide is reduced to examined the possibility of tive refraction. Possible zero, preventing the light wave modifying the way the light applications include lenses from propagating further. At travels by taking a normal that break traditional dif- this point, the light ray is per- transparent dielectric and fraction limits and manently trapped, its trajec- inserting tiny metallic inclu- ‘invisibility cloaks’. Sig- tory forming a double light- sions of various shapes and nificantly less research has cone that we call an ‘optical

A guided wave packet is efficiently injected from the ordinary waveguide to the LHH inside which it propagates smoothly owing to the slow “In quantum net- (adiabatic) reduction in the thickness of the core. works, information optically transmitted arrangements. As light focused on the potential of clepsydra. Each frequency passes through these struc- such structures for slow- component of the wave packet over the network is tures, oscillating electric ing, trapping and releas- is stopped at a different guide converted into mat- currents are set up that gen- ing light signals. Surpris- thickness, leading to the spa- erate electromagnetic field ingly, our analysis reveals tial separation of its spectrum ter, processed, and moments; these can lead to a critical point at which and the formation of a then converted back dramatic effects on the light the effective thickness of ‘trapped rainbow’.

into light”

Light Changed to Matter, Then Stopped and Moved

By converting that their discovery could pro- and extinguished in the light into matter and then vide a possible way to do this, first cloud are imprinted in back again, physicists since matter, unlike light, can this traveling component have for the first time easily be manipulated. and transferred to the sec- stopped a light pulse and The amplitude and ond cloud, where the re- then restarted it a small phase of the light pulse stopped captured information can distance away. This recreate the original light "quantum mechanical pulse. The period of time magic trick" provides un- when the light pulse be- precedented control over comes matter, and the mat- light and could have ap- ter pulse is isolated in plications in fiber-optic space between the conden- communication and quan- sate clouds, could offer tum information process- scientists and engineers a ing. tantalizing new window In quantum net- works, information opti- In a "quantum mechanical magic trick" for controlling and ma- cally transmitted over the devised by Harvard University physi- nipulating optical informa- network is converted into cists, a light pulse is extinguished in one tion; researchers cannot Diagram showing the time line for matter, processed, and ultracold atom cloud (purple), converted now readily control optical the Harvard research. then converted back into to matter and then revived in another information during its before being allowed to exit the second journey, except to amplify light. The physicists at cloud in its original state. Harvard University hope the signal to avoid fading.

page 10 photonics news 2008 Volume 10, Issue 01 sound success

Praveen Cheriyan Ashok represented ISP-SPIE Student Chapter in SPIE Leadership Meeting -2007 at Sandiego

Praveen Cheriyan He attended the SPIE scholar- Ashok who was the President of ship committee meeting and ISP student chapter for the year discussed the practical problems 2007 represented the chapter in faced by Indian students apply- the annual SPIE leadership meet ing for SPIE scholarships. He held at San Diego. During SPIE also presented a paper on Opti- Optics +Photonics Conference, cal metrology during Optics + he presented the work of chap- Photonics conference ter impressively in the meeting.

Placements of the first batch of Integrated M.Sc. (Photonics) 2007 students from CELOS

1. Aneesh Alex 6. Bejoy Varghese 10. Deepak Vijayakumar PhD student, Ph.D student, Ph.D student School of Optometry and Institute of Vision, University of Cameraino, DTU – Fotonik, Department of Photon- Cardiff University, United Kingdom. Italy. ics Engineering, Technical University of Denmark, 2. Harish Natarajan Swaha Krishnamoorthy 7. Priya Rose .T Denmark. Department of Physics, Ph.D student, Queens College of CUNY,USA. University of Naples, 11. Sreeja Thampi Italy. Ph.D student 3. Jithin Jose Gwaugju Institute of Science and University of Twente, Biophysical Engi 8. Jaya Mathews technology, neering (BPE), The Nether lands. Project Associate, South Korea. Experimental Optics (EXPO) 4. Sujith Manjooran lab, Department of Experimental Physics, IIT Madras, Chennai-600 036. 12. Nimi Gopalakrishnan National University of Ireland, Junior Research Fellow Republic of Ireland. C/O Dr. Kaustubh Rau 9. Aparna Das Lab 22, 5. Ranjini Raghunandan PhD student National Centre for Biological Sciences, PhD student, Sungyunwan University, TIFR,GKVK Campus, Department of Chemistry, South Korea. University of Basel, Switzerland. Karnataka, India-560065.

Harikrishnan S.B. Receives the Nalanda PSI-2007prize to Shaija P.J. Endowment Prize-2008

Mrs. Shaija Johnson receives the Photonic Society of India Prize of the year The 2008 Nalanda 2007 who became first rank in M.Tech De- Endowment Prize will be gree Examination in Optoelectronics and presented to Mr. Harikrish- Laser Technology conducted by CUSAT. nan S.B during the inaugural The PSI prize is given every year to the stu- function of APW-2008. The dent who stands first in M.Tech Degree Ex- Nalanda Endowment Prize amination (OE<) of Cochin University Of is instituted by Prof. N. G. Science and Technology. This prize is Devaki of Department pf instituted by Prof. C.P Girijavallabhan, Di- Hindi, CUSAT. This prize rector, CELOS. The prize which in cash, includes cash, memento and memento and merit certificate will be presented duringthe inaugural merit certificate and is given every year to the student function of APW 2007. Mrs. Shaija is at present working as a lec- who stands first in the First Semester Examination of turer in Model Engineering College, Thrikkakara. Integrated M. Sc (Photonics) Degree of CUSAT.

photonics news 2008 page11 ISP-SPIE student chapter activity

The ISP-SPIE Student Chapter activities in the year 2007

The ISP-SPIE Student Chap- the school children the munity as a whole as it gave a ter was established in 2005 with an miraculous world of light good understanding of the speci- aim to be the part of the largest inter- in a simple and attractive fied topics in an elegant manner. national force for the exchange, col- manner. The ‘Optics Fair’ was a huge suc- lection and dissemina- The regular ac- cess with the school students wel- tion of knowledge in tivities were comple- coming such a noble move. Their Optics, Photonics and mented by the teachers’ acknowledgment has motivated Imaging. The present day celebration (Sept-5), us to design and plan for a better office bearers were Environmental day cele- Optics fair in the coming years. elected on January 18, brations (Jun-5), Yoga All the volunteers played their 2007. Then the chapter Class, and Neuro linguis- part well in the optics. This effort was on the move. The tic Program which all en- has been acclaimed by the SPIE. chapter has organized hanced the personalities of Now the Chapter is respected many activities to en- the chapter members. The globally. This respect endowed hance the scientific and Tuesday seminars, was a on us is a mark of achievement of social attitudes of the chapter mem- venue for all the members the Chapter. bers. to speak on scientific top- We would like to men- The chapter activities were ics which later became hot tion with Gratitude the contribu- given a kick-off with the blood dona- discussions. This was a tion of Mr. Jijo P.U., Mr. Rajesh tion camp which was a success, with good event to enhance the M, Mr. Thomas Johny in shaping the whole support and contribution. scientific inquisitiveness of the Chapter. Special mention to “The chapter ac- After this, many events have taken the students. Mr. Jenu V. Chako for designing place, which exhibited the power and The lecture series the posters, for schools and Mr. tivities were imagination of the chapter members. by Prof. Rajaram Nit- Siddarth Joshi for designing the given a kick-off The two ‘optics to school’ held to yananda, Prof. M. website of the chapter, Bhavans Girinagar and Rural high Lakshmanan and Prof. www.spie.in. A new post of Joint with the blood school Thumpur proved that the Ajoy Ghatak was very secretary is being made to make donation camp members are capable of explaining to useful to the student com- the working smoother. which was a

grand success” Optics Fair 2007 was organized by the ISP-SPIE Student Chapter

Optics Fair 2007 school students the real was organized by the ISP- world of Optics and Light. SPIE Student Chapter on The fair was open to a 17-18 October 2007. The wide range of student program was a big success ages, so activities had to with more than 1300 school be designed that were students participating in the appropriate for all abili- two day event. The feed- ties. The main idea behind back we received was over- this fair was to introduce whelming. The enthusiastic the younger kids to the and motivated faces of the magnificent field of Optics school students told us di- in a simple manner. High rectly of the success of the School students were ex- program. The Optics Fair posed to more facts with was the largest event con- the goal to motivate the ducted by the chapter in its higher secondary students three year history. Chapter to pursue the field of Op- members were enthusiastic tics. The event also proved about this event from the a good occasion to teach beginning and excited to the topics taught in the get a feel for teaching schools in a better way.

page 12 photonics news 2008 Volume 10, Issue 01 in the lime light...

Seminars by visitors

18-01-2007: “Laser based technologies for ADRIN, Department of Space Secun- versidad de Conception, Casilla-160C, detection of trace”, by Dr. Jaipal Dudeja, derabad. Conception, Octava Region, Chile. Laser science and Technology Centre, New Delhi. 24-09-2007 to 26 -09-2007: Lecture series 31-12-2007: “Understanding the Uni- on “Optics and Quantum mechanics”, by verse : New insights and Challenges”, 02-02-2007: “Optical Networks”, by Mr. Prof. Ajoy Ghatak, Emiretus Professor, by Prof. T Padmanabhan, IUCAA, George Mathew, Deputy General Manager, Indian Institute of Technology, Delhi. PUNE. Southern Telecom Region, BSNL, Ernaku- lam. 29-10-2007: “Photonic Band Gap Materi- 10-01-2008: “Femtosecond lasers and als: Semiconductors of Light”, by Prof. Ultra fast processes”, by Dr. Reji 13-03-2007 to 15-03-2007: Lecture series on Sajeev John, Department of Physics, Uni- Philip, Raman Research Institute, “Linear and Nonlinear Dispersive Waves: versity of Toronto, Canada. Bangalore. Solitary Waves, Optical solitons vs comput- ing”. By Prof. M Lakshmanan, Centre for 06-12-2007: “Laser Speckle Imaging and 18-01-2008: “Ultra fast nonlinear spec- Non linear Dynamics, Bharathidasan Uni- Analysis for Functional and Anatomical troscopy”, by Prof. Ajoy Kumar Kar, versity, Tiruchirappally. Imaging of Brain”, by Dr. Suresh Paul School of Engineering and Physical Joseph, TOCH Institute of Technology. sciences, Heriot-Watt University, Ed- 28-06-2007: “Dynamics of Coupled Cellular inburgh, UK. oscillators: Applications to Circadian Sys- 10-12-2007: “Structural, Electrical, Ther- tem”, by Dr. P Indic, Medical School, Uni- mal and Spectroscopic characterization versity of Massachusetts. of LiMn2O4”, by Dr. Thomas Lee, Depar- tamento de Fisica, Universidad de Con- 19-07-2007: “Imaging advances in radiation ception, Casilla-160C, Conception, Oc- therapy”, by Ms. Geetha Menon, Medical tava Region, Chile. Physicist, Cross Cancer Institute and Uni- versity of Alberta, Edmonton, Canada. 10-12-2007: “Photo thermal Radiometry: A tool for subsurface studies”, by Dr. 16-08-2007: “Elements in Image Process- Jyotsna R, Departamento de Fisica, Uni- ing”, by Dr. T P Sasikumar, Scientist,

New Doctorals from ISP

Pramod Gopinath Santhi.A.Joseph Sr.Ritty has received his has received her PhD J.Nedumpara PhD for the thesis for the thesis titled has received titled ‘Studies on ‘Investigations of her PhD for Optical and X-ray optical interaction the thesis ti- Emission Processes processes in certain tled ‘Studies in Laser Produced photonic materials on ASE, Plasma’. He has using z-scan and Lasing and NLO Characteristics in completed his doctoral work under thermal lens techniques’. She has com- Certain Laser Dyes’. the guidance of Prof. V P N Nam- pleted her doctoral work under the guid- She has completed poori. ance of Prof. V P N Nampoori. and Prof. her doctoral work under the guid- Now he is working as Reader in P Radhakrishnan as co-guide. ance of Prof. P Radhakrishnan. Physics Faculty of Applied Sciences Now she is working as a lecturer at Indian Institute of Space Science and Now she is working at Service d'Op- Vimala College, Thrissur. Technology. tique et d'Acoustique, Université Libre de Bruxelles, Belgique.

“The only source of knowledge is experience”...

photonics news 2008 page13 Sibilathullah A.M’s unexpected death took away one Photonics Commu- of the exceptional promise from the family of Photon- ics. At the time of his untimely death, he was a stu- nity of CUSAT dent in the third batch of Integrated M. Sc (Photonics). Mourns the Demise He was very active in all the events that tookplace at of Sibilathullah A.M. International School of Photonics and CELOS. He was native of Calicut district and joined CELOS in the year 2003.

Publications...

Recent publications from ISP

1. Achamma Kurian, Sajan D. George, C.V. Bindhu, and polymer matrices under pulsed laser excita- V.P.N. Nampoori and C.P.G. Vallabhan, “Thermal tion”; Journal of Photochemistry and Photobiology lens technique to study the effect of pH on electronic A:Chemistry, (2007). energy transfer in organic dye mixtures”; Spectro- 10. Mandamparambil Rajesh, Mavila Sheeba, Karinja- chimica Acta Part A: Molecular and Biomolecular manna Geetha, Chakkalakkal P.G. Vallaban, Padma- Spectroscopy, 67, Issues 3-4, July 2007, Pages 678-682 nabhan Radhakrishnan, and Vadakkedathu P.N. 2. Annieta Philip K, Lyjo K. Joseph, Litty M. Irimpan, Nampoori; “Fabrication and characterization of dye- Bindu Krishnan, P. Radhakrishnan, V. P. N. Nampoori doped polymer optical fiber as a light amplifier” and Raghu Natarajan; “Thermal Characterization of Applied Optics. 2007, 46, Issue 1, pp. 106-112. Ceramic Tapes using Photoacoustic Effect”; Physica 11. M. Sheeba, K.J. Thomas, M. Rajesh, V.P.N. Nam- Status Solidi (a), 204 (3), 737 (2007). poori, C.P.G. Vallabhan, P.Radhakrishnan; 3. Jayasree V.K, Shaija P.J, Manu P. John, P. Rad- “Multimode laser emission from dye doped poly- hakrishnan; “An Optoelectronic Sensor Configura- mer optical fiber.”; Applied Optics, Vol 46, 8089- tion for the Determination of Age Related Indices 8094, 2007. Using Blood Volume Pulse”; Sensors & Transducers, 12. P.M. Sandeep, S.W.B. Rajeev, M. Sheeba, S.G. vol.87, Jan.2008, pp 39-45. Bhat and V.P.N. Nampoori; “Laser induced fluores- 4. Jayasree V.K, Shaija P.j, V.P.N Nampoori, C.P. Giri- cence based optical fiber probe for analyzing bacte- javallabhan, P. Radhakrishnan; “A simple and novel ria”; Laser Physics Letters, 1-5 (2007). integrated opto-electronic system for blood volume 13. Ritty J. Nedumpara, Geetha K, Dann V. J., V. P. N pulse sensing and heart rate monitoring”; Interna- Nampoori, C.P.G. Vallabhan and P. Radhakrishnan; tional Journal of Optomechatronics, 1: 359-368, 2007. “Light amplification in dye doped polymer films”; 5. Jinesh Mathew, K. J. Thomas, V. P. N. Nampoori J.of Opt.A:Pure and Appl.Opt.9 (2007) 7-14. and P. Radhakrishnan, "A Comparative Study of Fi- 14. Ritty J. Nedumpara, Thomas K. J., Jayasree V. K., ber Optic Humidity Sensors Based on Chitosan and C.P. Girijavallabhan, V.P.N. Nampoori, P. Rad- Agarose"; Sensors & Transducers Journal, Vol.84, Is- hakrishnan; “Study of solvent effect in laser emis- sue 10, October 2007, pp. 1633-1640. sion from Coumarin 540 dye solution”; Applied 6. Litty Irimpan, Bindu Krishnan, A. Deepthy, V.P.N Optics 2007. Nampoori and P. Radhakrishnan; “Size dependent 15. Samuel Varghese, Muhammed Iqbal, Suresh Nair, enhancement of nonlinear optical properties in nano V.P.N. Nampoori and C.P.G. Vallabhan; “Fabrication colloids of ZnO”; Journal of applied physics, 103, and Characterization of Monolithically Fused 033105 (2008). Wavelength-Independent1X4 Couplers”; Fiber and 7. Litty Irimpan, Bindu Krishnan, A Deepthy, V.P.N Integrated Optics 26, 245–254 (2007). Nampoori and P. Radhakrishnan; “Excitation wave- 16. Sajan D. George, A.K. George, P. Radhakrishnan, length dependent fluorescence behaviour of nano V.P.N. Nampoori and C.P.G. Vallabhan; “Photo colloids of ZnO”; J. Phys. D: Appl. Phys. 40, 5670 acoustic studies on thermal parameters of liquid (2007). crystal mixtures”; Smart Materials and Structures 8. Litty Irimpan, A. Deepthy, Bindu Krishnan, V.P.N 2007. Nampoori and P. Radhakrishnan; “Size dependent 17. V.J. Dann, Manoj V. Mathew, V. P. N. Nampoori , fluorescence spectroscopy of nanocolloids of ZnO”; C.P.G. Vallabhan, V.M. Nandakumaran, P. Rad- J. Appl. Phys. 102, 063524 (2007). hakrishnan; “Spectroscopic Characterisation of La- 9. M Kailasnath, P.R. John, P.Radhakrishnan V.P.N ser Induced Plasma from Titanium Dioxde”;Plasma Nampoori and C.P.G Vallabhan, “A comparative Science and Technology, 9(4), 456- 459 (2007). study of energy transfer in dye mixtures in monomer

And the last word… “ Live as though you will die tomorrow but learn as though you live for ever” -Gandhiji

page 14 photonics news 2008 Volume 10, Issue 01 PICTURE PARLARE

photonics news 2008 page15 International School of Photonics

International School of Photonics (ISP) came into existence Cochin university of science and technology in 1995 by restructuring and delinking the laser laborato- Cochin 682022 ries along with the faculty members of the laser group from Kerala the Department of Physics at Cochin University of Science India and Technology. Manpower development and establish- ment of research activities in photonics and related fields are the major objectives of ISP. We have a four semester Phone: +91-484-2575848 Fax: +91-484-2576714 M.Tech course in Optoelectronics and Laser Technology . mail us @ : [email protected] In 2001 we also started an M.Phil. course in Photonics with an objective to train teachers in the area of Photonics.

ISP is a one among the three participating departments in the UGC sponsored Centre for Excellence in Lasers and Optoelectronic Sciences (CELOS)

visit us @ www.photonics.cusat.edu Light matters……..

Indo –UK Workshop on Fibre optics and Applications

September 2008. Photonics specialists International School of Details will be available in from various R&D institutions and Photonics, CUSAT is organizing Universities from India and UK will www.photonics.cusat.edu Indo-UK Workshop during take part in the Workshop. by the month of March.

CALL FOR PAPERS PHOTONICS - 2008 International Conference on Fiber users actively engaged in the area of exhibition would also be organized concur- Optics and Photonics INDIAN Photonics. Inauguration would be held at rently with the conference. In addition a techno- INSTITUTE OF TECHNOLOGY DELHI New the Convocation Hall of IIT Delhi on the commercial evening session would be organ- Delhi, India, December 13-17, 2008. evening of December 14 while main con- ized on day 2 of the conference in which manu- Photonics-2008 is the ninth in the series of bien- ference (December 15-17, 2008) would be facturers and service providers related to Opti- nial international conference in the general area held at the Habitat World Convention cal Telecommunication and Photonics in general of Photonics held in India since 1992. It provides Center. On December 13-14, tutorial could make presentations of their company a forum for interaction and exchange of ideas courses on some of the conference topics profile and advertise at a nominal fee for the among scientists, engineers, researchers, and would be held at IIT Delhi. A technical time and the venue.

Do you dream optics and photonics? Be a member of OSA and SPIE where science and technology innovators in optics and photonics come together. Login @ http://www.osa.org/membership/join.aspx & http://spie.org/x1720.xml

The Optical Society of America

Printed and published by Prof. VPN Nampoori, Director, International School of Photonics, CUSAT, Kochi-682022