g io i - - ( o w t e ) m JAN 2 61990 SYMPOSIUM ON QUANTUM ELECTRONICS UNIVERSITY OF POONA JANUARY 1-3. 1981 S T t t EXTENDED ABSTRACTS OF CONTRIBUTED PAPERS UNDER THE AUSPICES OF DEPARTMENT OF ATOMIC ENERGY GOVERN M3 im Q Frrlfm A F THIS DOCUMENT IS UN; ‘I iTEO DISCLAIMER Portions of this document may be illegible in electronic image products. Images are produced from the best available original document. ORGANISING COMMITTEE D. D, Bhawalkar U. K- Chatterjee Mrs. N. Y. Mehendale Convener Secretary Local Secretary BARC, Bombay. BARC, Bombay. Univ. of Poona, Pune- G. Chakrapani B. Ghosh V. V. Itagi I IT, Kanpur, BARC, Bombay, Marathwada Univ. Aurangabad. J. P. Mittal A. S. Nigvekar U. Nundy BARC, Bombay. Univ. of Poona, Pune. BARC, Bombay. B. S. Rate! M. K. Raghvendra Rao N. Ramaswamy DSL, Delhi. BARC, Bombay. DAE, Bombay. SYMPOSIUM ON QUANTUM ELECTRONICS UNIVERSITY OF POONA JANUARY 1-3, 1981 ■ # !> EXTENDED ABSTRACTS OF CONTRIBUTED PAPERS UNDER THE AUSPICES OF DEPARTMENT OF ATOMIC ENERGY GOVERNMENT OF INDIA DISTRIBUTION OF THIS DOCUMENT IS UNLIMITED n o u u SUBJECT IHPEX GROUPS PAGES I . LASERS 1-go I I . QUANTUM OPTICS 91-118 I I I . NOHLDIEAH OPTICS 119-150 17. LASEB PHOTO-CHBHISTEY 15U166 V. LASEB SPECTROSCOPY 167-196 7 1 . LASEB SCATTERING 197-212 T H i LASER PRODUCED PLASMAS 213-2)2 ,7111. LASEB APPLICATIONS 233-26) LASERS Water Dielectric coaaxial cstole driven 1 multigas laser system. - V.V.Itagi and A.H.Khan. An ultraviolet pumped Nitrogen laser * with a water dielectric capacitor. - S.Thattey. Spectral output of Np lasers at 337.1 ran 8 - C.Lal and S.N.Thakur. A symmetry in the laser output from 11 transversely excited N2 la9er - C .lal, J.P.Singh and S.N.Thakur. Analysis of Nj-laser with triggered and 15 untriggered spark-gap. - S.Thattey* Polarization properties of internal 19 m irro r multimode He-Be la s e r - D.Sen, F.N.Puntambekar, H.S.Dakiys and V.T.Chitnis. Excitation tremsfer by atom-atom and 22 electron-atom collisions among excited states of Neon. - V.D.Dandawate. Time resolved studies in pulsed Argon 26 ion laser - V.Hari, C.Chakrapani, P.B.K.Sarma,^ P.B. Bao and P. Venkateshwarln. Intensity distribution in Excimer 50 transitions of NeE, Arl’ and KrP. - T .T .I ta g i and B .S.B halekar. Effect of Tripropylamine in ballast 55 resistance type TEA C02 lasers. - (J.K .Chatterjee, U.Nundy, A.K.Nath and N. 3.3 hik arkhane. M ultiline injection locking in TEA GO^ 57 laser. - A.K.Nath and (J.K.Chatterjee. Discrepancy of 0- concentration in the 41 dissociation products of a sealed TEA C02 laser - D.J.Biswas and G.K.Chatterjee 13. Problems of Simultaneous triggering of 45 two coaxial plasma tubes in a CW CO^ la s e r . -3.L.Gupta, B.S.Narayan and l.M.Kukreja. 14. Some new laser dyes - M.B.Padhye, 48 T.3 .Varadarajan and A.V.Deshpande. 15. Optical gain in the Ranipal-S laser 56 Dye - V .V .Itagi and B.H.Pawar. 16. Effect of Hydrogen bonding on DAMC 59 Dye laser characteristics. - V.Masilamani and B.M.Sivaram. 17. Efficiency of energy transfer Hh-6G- 63 Hh-3 Dye Laser - P.J.Sebastian and X .Sathianandan. 18. Solvent effect on amplified spontaneous 66 emission of Anthranilic acid - S.Y.Itagi and A.Kulkarni. 19. Antistokes fluorescence in Neutral Bed 70 ex c ite d by 632.8 nm He-Ne la s e r . - S.Y.Itagi and A.Kulkaml. 20. Spectral evolution of a laser pump 74 grating tuned Dye Laser - K.Dasgupta and L.G.Nair. 21. A double pulsed Ruby laser for pulsed 78 holography - R.Chari, G.Chakrapani, Bh.A.R.B.Raju, K.R.Sarma and P.Venkateswarlu. 22. Study of thermal lensing in a high power 82 NdtGlass amplifier using a wavefront shearing interferometer. - L.J.Dhareshwar, T.P.3.Nathan, J.S.Uppal and 9.L.Gupta. 23. Transient lens measurement in optically 86 pumped glass am plifier ▼ T.P.3.Nathan, J.S.Oppal, L.J.Dhareshwar, B.S.Narayan and D.D.Bhawalkar. WATER DIELECTRIC COAXlAi CABLE DRIVER MULTIGAS LASER StSTEM. V .V . Itagi and A-R- Khan Department of Physics Maratbwada University Aurangabad 431004, India In recent years substantial efforts have gone into the development of excimer lasers because of their . potentiality of high power .in the ultraviolet region of the spectrum. These lasers have provided experi­ mentalists with a new and versatile tool for spectro­ scopic and photochemical investigations. Pumping of these excimers, in particular, rare-gas halide excimers has.been accomplished through (a)high energy pulsed electron beams (b)electron beam sustained discharges and (c)ultraviolet preionized avalanche discharges. Though higher efficiencies have been achieved in electron beam pumping, the laser pumped by fast transverse discharge is a convenient laboratory instru­ ment of small size. Discharges of this type have been used in the past for pulsed N 2 and CO? lasers. Many different configurations have been used for the. power supply. These include discrete capacitors1»2', Blumlein circuits with strip transmission lineso»4 and charged coaxial cables'. These networks use solid dielectrics and suffer from dielectric fatigue and breakdown. This difficulty has been overcome by using a water dielectric B lu m le in S , Pure water has high electrical breakdown strength.for'pulse" loading of the order of a micro­ second or less' and is self healing. , since water possess an exceptionally high dielectric constant V € = 80) throughout a broad frequency range,, it permits the fabrication of a low-impedance transmission line with very compact physical dimensiongL We have combined these Useful properties of water and certain advantages of- coaxial, cable discharge in the laser design under report.■ The; power supply to the laser head consists of a parallel array of charged water dielectric coaxial cables.. Each cable is a one foot long aluminium tube with a copper coated m.s. welding rod mounted along the tube axis. Deionized water is made to flow in the intervening space. These cables directly terminate into the laser electrodes. Both the electrodes have chaiig profile® and' are 30cms. long. The anode is a. solid., metal bar and the cathode is made 2 hollow and is covered with monel mesh with an ultra-.- violet preionizer system behind- it. The preionizer is driven by a separate cable. The laser body is all metal and hence can withstand pressures of several atmospheres. The laser head, the electrodes and the preioni­ zer system are all demountable. So also are the windows and the- reflector mounts. These arrangements help to run the laser with different gases at required pressures along with the necessary optics that goes with each type of laser. Since water has to be loaded with short duration pulses a two stage Marx generator has been used to supply power to the system through pulse shaping pressurized; switch. The schematic of cable pulse- forming network is shown in fig .2. The details of the laser system and of the preliminary investigations performed with N 2 a s l a s e r gas will be presented. We are grateful to the Atomic Energy Commission of India for the financial support REFERENCES 1. R.Burnham, N . w . H arris, and N.Djeu, Appl.Phvs.Lett. 28, 86(1926). 2. R.Burnham and N.Djeu, Appl.Phys.Lett.29,/0 /(19/6). 3. B.Godard and M.Vannier, Opt.Commun.187206(19/6). 4 • C .P.Christensen, L.W.Braverman, W .H.gteier, and G -W ittig. A P P l.P h y s .L ett. 29,424(19/6) • 5 . R-C-Sze and P.B.Scott. J.Appl.Phys. 4/,5492(19/6). 6. J .I.Levatter and R.s.Bradford, Jr.Appl.Phys.Left. 33, 242(19/8). /. D.B.Fenneman and :R.J .Gripshover Digest of Technical Papers, Second I.E-F.E. Pulsed Power Conference p. 122 (19/9)'. ' 8. T.Y.Chang, Rev.Sci.Instr. 44, 405(19/3)• - 3 - ■ f r e t o ni ^ e r -Mesli colhode -Win d o u-i -Ar-io <d Q 73" -Water- cdi<stec.fr- i c cable arrta v = 7 M, Fig. 1. End v iew s c h e m a tic o j . the- X -aser-. S w itc h " ^ L a e e r - E l 'ig.3. 5 c hem ati c o j , cable PFU . - 4 - AN DMBAVIOIEl POISED NITROGEN LASER WITH A WATER DIEIECTSIC CAPACITOR O.O. BHAUALKAR, Sudhir THATTEY, Pradeep.AGRAUAL, Swapan CHATTERIEE Bhabha Atomic Research Centre Bombay-400 085 The Nitrogen laser is an important source of pulsed UV radiation for pumping dye lasers, photochemistry, spectroscopy etc. The laser can be fabricated in a moderately equipped laboratory. Due to the short life time of the upper laser level, the excitation to this laser has to be very fast, typically within 10 nsec. This requires ultra-loui—inductance capacitors for storing the electrical energy. Ida report here the fabrication of a. Nitrogen laser which uses a water dielectric flat plate transmission line. Water as a d ie le c tr ic has two main advantages, namely a very high dielectric constant (~ 80) and a high pulsed dielectric strength (~ 1 MU/cm). Thus in a given volume, water dielectric can store a considerably larger amount of energy than, say the fibre glass epoxy laminate. Further, water being a liquid is self healing. The conductivity even of distilled or deionized water is sufficiently high to discharge the energy stored in the dielectric in a few micro-seconds.