SK2811 Fiber-Optical Communication Lecture 12 from Khz To

Home , Edwin Howard Armstrong, Guglielmo Marconi

SK2811 Fiber-Optical Communication Outline

Lecture 12 • The evolution of radio communication • The evolution of optical communication

From kHz to THz • Current research and the future (next lecture)

The development of radio and fiberoptics and the pioneers behind it

Richard Schatz [email protected] Grimeton 5bps@17 kHz VLF transmitter from 1924, Hecto transmitter (100Gbps@200THz) from 2010, Kista, 08-7904069 Sweden Laboratory of Varberg, Sweden Laboratory of KTH 2012 PHOTONICS PHOTONICS

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The Dawn of Radio Radio Evolution vs Photonic Evolution

1887 Spark gap Transmitter

On-Off keying

James Clerk Maxwell, Scotland Heinrich Hertz, Germany (1831-1879) (1857-1894)

Published 1864 ”The Dynamic Demonstrated radio waves 1887 Theory of Electromagnetic Fields” Proposed electromagnetic waves

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and and MICROWAVE Eng. MICROWAVE Eng. Guglielmo Marconi (1874-1937), Italy Marconi´s Equipment

”Father of wireless telegraphy” Spark transmitter Developed tuned receiver and transmitter designs Works like a buzzer Patent on ”Telegraphy without wire” 1896

1895: Transmitted 1 km Coherer receiver 1897: Transmitted 15 km 1901: Transmitted over the Atlantic

Received Nobel Prize 1909

Contains metal filings and changes resistance when exposed to a radio pulse Invented by Edouard ...but neither the spark transmitter nor the Branly 1890, France coherer was suitable for audio transmission Laboratory of Laboratory of PHOTONICS PHOTONICS

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Radio Evolution vs Photonic Evolution Valdemar Poulsen (1869-1942), Denmark

Valdemar Poulsen discovered 1903 that the 1887 1903 First arc pulsating flame between two carbon electrodes Spark gap not only produced sound (William Duddel´s Transmitter transmitter with singing arc 1899) but also emitted continuous continuos radio waves with a frequency determined by a On-Off radio waves tuned circuit keying On-Off Arc generator worked best around 10 kHz and keying used a frequency multiplier to reach above 100 kHz.

Modulation first with FSK but later on-off with absorber

Poulsen also invented the magnetic recorder.

Poulsen Arc Radio Transmitter, 1903

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and and MICROWAVE Eng. MICROWAVE Eng. Radio Evolution vs Photonic Evolution Reginald Aubrey Fessenden (1866-1932), Canada

1887 1903 1906 Spark gap First arc First radio Invented the electrolytic detector Transmitter transmitter broadcast of with voice and continuos music On-Off radio waves December 23, 1900 (?) keying AM On-Off First audio transmission trial with speech using modulation keying spark transmitter over 1.6 km. Probably no listeners.

December 24, 1906 (?) Transmitted recording of Händels opera Xerxes, Ernst Holy Night on violin (played by himself) and Alexanderson recitation of the Bible, using a rotary spark transmitter at 100 kHz designed by swedish inventor (1878-1975) Ernst Alexandersson from Uppsala. KTH 1900 Emigrated to USA 1902 Laboratory of Laboratory of PHOTONICS PHOTONICS

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Fessendens equipment The Cat's-whisker (Crystal) detector 1906 Rotary HF generator

AC-Generator with up to 22000 rpm and 600 poles

One Alexanderson transmitter from 1924 is still functional in Grimeton, Varberg.

Electrolytic detector

DC biased thin platinum wire • An galena (lead sulphide), iron pyrite, silicon or SiC crystal was touched by bronze wire to in nitric acid rectify the radio waves The electrical resistance due to • The rectifying effect was discovered by Ferdinand Braun at University of Würzburg 1874 electrolysis will vary strongly with voltage • Developed for radio by G. W. Prickard and patented 1906

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and and MICROWAVE Eng. MICROWAVE Eng. Lee de Forest (1873-1961), USA First Vaccum Diode Detector

Thomas Alva Edison Proposed to his first wife with wireless telegraphy 1906. She (1847-1931), USA Edisons light bulb The Fleming valve Edison effect, 1880 Sir Ambrose accepted but divorced him after six Fleming months. Edison working with light bulbs noticed that carbon Fleming understood that (1848-1945), UK from one end of filament would be deposited on the the "Edison effect" could inside walls of the bulb, turning it black. be used to rectify a First vaccum diode Added a separately biased grid to Flemings two-electrode vacuum tube from 1904 and wireless signal and detector 1904 discovered that he got better reception. He called the first triode valve ”the Audion”, 1906. But Edison constructed a light bulb with a third electrode developed a dedicated it was messy to use and no one understood its use as an amplifier until 1911... and showed that the particles were negatively "Fleming valve" to charged and generated current in the extra electrode demonstrate it Introduced the word ”radio” and proposed and started public broadcasting 1910. if it was positively biased Laboratory of Laboratory of PHOTONICS PHOTONICS

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Radio Evolution vs Photonic Evolution Edwin Howard Armstrong (1890-1954) USA

1887 1903 1906 1914 Spark gap First arc First radio First Transmitter transmitter broadcast of coherent with voice and radio continuos music transmitter On-Off radio waves keying AM AM On-Off modulation modulation keying

• Armstrong studied the Audion theoretically and experimentally and developed it further. • Invented the regenerative receiver September 22, 1912 when he was 22 years old • Discovered that the Audion could also work as an oscillator and transmitter, 1913 • When De Forest learned this he had already sold the patent rights for the Audion to AT&T and started instead a patent fight with Armstrong for the regenerative receiver and transmitter

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and and MICROWAVE Eng. MICROWAVE Eng. Radio Evolution vs Photonic Evolution John Renshaw Carson (1886-1940), USA

1887 1903 1906 1914 1915 Spark gap First arc First radio First SSB Transmitter transmitter broadcast of coherent modul- with voice and radio ation continuos music transmitter On-Off radio waves keying AM AM On-Off modulation modulation. keying

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Radio Evolution vs Photonic Evolution The Superheterodyne Receiver Invented by E. H. Armstrong 1918 1887 1903 1906 1914 1915 1918 Spark gap First arc First radio First SSB Super- Transmitter transmitter broadcast of coherent modul- hetero- with voice and radio ation dyne continuos music transmitter receiver On-Off radio waves keying AM AM On-Off modulation modulation. keying

Benefits: • Heterodyning provides gain (Signal+LO) 2=Signal 2+2Signal .LO +LO 2 and translates carrier

frequency: f IF =fsignal - f LO  • Tuning provided by a local oscillator • The selectivity and gain provided by a fixed frequency IF amplifier • Amplitude and phase information in carrier is preserved ⇒ Compatible with any modulation format and detector type.

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and and MICROWAVE Eng. MICROWAVE Eng. Armstrong on top of RCAs broadcasting tower, 1923 Armstrongs wedding present to Marion, 1923 Armstrong liked high heights. On May 15, 1923 Armstrong made stunts on the 120 m high RCA broadcasting tower Why? Maybe to impress his girlfriend Marion or to annoy his boss Sarnoff. He succeeded with both!

A ”portable” superheterodyne receiver!

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Radio Evolution vs Photonic Evolution FM-modulation by Armstrong, 1933-35

1887 1903 1906 1914 1915 1918 1933 • Much less interference and better Spark gap First arc First radio First SSB Super- FM sound quality but needed larger Transmitter transmitter broadcast of coherent modul- hetero- modul- bandwidth and higher frequency with voice and radio ation dyne ation. • RCAs president Sarnoff was not continuos music transmitter receiver On-Off interested since new receivers were radio waves keying needed and TV R&D was more AM AM FSK keying important modulation modulation. • Armstrong resigned and started own company

Armstrongs FM-transmitter

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and and MICROWAVE Eng. MICROWAVE Eng. Armstrongs Catastrophe The End Game

• Armstrong licensed FM receivers and transmitters in the 40 MHz band Lee de Forest : Armstrong is gone • When RCA noticed the success of FM, Sarnoff lobbied FCC to make 88-108MHz and I am alive, well and happy, and standard and started own transmissions without paying royalty hope to live for many years more. • Armstrong instituted a lawsuit against RCA 1948 What a contrast! • After five years of fruitless fighting and desperate economic situation Armstrong grew Lee de Forest wrote an autobiography called bitter and Marion divorced him ”Father of Radio”. But only 54 copies of 5000 were • He comitted suicide Feb. 1, 1954 sold during 1953. He asked then his wife to write an autobiography called ”I Married a Genius” but she never finished it...

Lee de Forest continued research at his laboratory but failed to get funding and died with only $1250 in cash

Marion Armstrong fought for Howard Armstrongs reputation as a great inventor and won all of his FM patent suits and lived a life in luxury until her death 1979

David Sarnoff at RCA Laboratory of Laboratory of PHOTONICS PHOTONICS

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Radio Evolution vs Photonic Evolution FM stereo system, approved by FCC 1961

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and and MICROWAVE Eng. MICROWAVE Eng. Radio Evolution vs Photonic Evolution The Photophone: the dawn of photonics

1887 1903 1906 1914 1915 1918 1933 1961 • First wireless telephone system invented by Alexander Graham Bell and Sumner Tainter 1880 Spark gap First arc First radio First • Transmitter: sunlight reflected by a thin microphone membran Transmitter transmitter broadcast of coherent SSB Super- FM FM stereo • Receiver: Parabolic mirror with crystalline selenium cell in focal point that modulated the current with voice and radio modul- hetero- modul- Broad- through an earphone continuos music transmitter ation dyne ation. casting On-Off radio waves receiver keying AM AM Subcarrier FSK keying modulation modulation. FM modulation.

But the first wireless transmission was not with radio!

In april 1880 Bell and Tainter demonstrated ..but it could only be used in line of sight the photophone by transmitting 213 meters in clear sunny weather from Bells Laboratory in Washington D.C. ... a better light source and transmission medium were needed

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The first LED Losev´s Optical Communication Patent 1927 (granted 1929)

"The proposed invention uses the known phenomenon of luminescence of a carborundum detector and consists of the use of such a detector in an optical relay for the purpose of fast telegraphic and telephone communication, transmission of images and other applications when a light luminescence Henry J. Round, UK Oleg Vladimirovich contact point is used as the light source (1881- 1966) I–V characteristics of a Losev, Russia connected directly to a circuit of modulated carborundum detector (SiC) current." Radio pioneer indicating the onset of light (1903-1942) Assistant to Marconi emission 1928 Developed SiC LED Round, H. J. Electr. World, 49, 308 (1907) Electroluminescence in Losev, O. V. Luminous carborundum 1923-1941 In Losev s autobiography he wrote November detector and detection effect and 1941 “using semiconductors, a tree-terminal forward biased cat oscillations with crystals , Phil. Mag. 6, whisker SiC detector 1024–1044 (1928) system may be constructed analogous to a 1907 The paper also includes [vacuum] triode” observation of RF oscillations due to negative resistance ...but the manuscript was lost on way to editor in Kazan and he died of hunger the same year during the german siege of Leningrad...

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and and MICROWAVE Eng. MICROWAVE Eng. The Discovery of the High Efficiency LED Development of LED Efficiency

Rediker and his team did research on semiconductor diodes at Lincoln Laboratories. Instead of mainstream silicon they switched White 231 lm/W Maximum possible : to GaAs because its higher mobilty Green 687 lm/W White 251 lm/W They were the first to fabricate a diffused pn-junction diode and made also a GaAs alloyed diode but the two types of diodes had Rubin Braunstein, Robert H. Rediker, MIT very different I-V characteristics!? RCA, USA Lincoln lab, USA (1924-) Schematic of first pn-junction (1922-) First diffused GaAs Rediker decided to investigate the reason by observing luminescence GaAs diode Electroluminescence LED + Optical free at 77 K with a spectrometer. When the diffused diode was in GaAs 1955 space video measured the spontaneous emission was three orders of (and in GaSb, InP, transmission over 50 magnitude higher and the spectrometer was pinned: 85% SiGe) km, 1962 quantum efficiency!

with R. J. Keyes and T. M. Quist, They reported results at the Solid State Device Research presented at the Solid State Device Research Conference, Conference, Durham, N.H., July 1962. Among the participants Durham, N.H., July 1962 . were Bob Hall and Nick Holonyak of General Electric... Dupuis et al.JOURNAL OF LIGHTWAVE TECHNOLOGY, VOL. 26, NO. 9, MAY 1, 2008

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The First Laser The first Experimental Observation of Lasing

Theodore Maiman and Irnee D’Haenens worked with ruby lasers despite that Schawlow t al. at Bell Labs had dismissed the material as unsuitable and the management at Hughes Research Laboratories in Malibu, California had wanted to stop his work. But they continued ...

Succeeded to observe lasing in a Charles H. Townes Arthur L. Schawlow Theodore H. Maiman, Here it is! Nicolay G. Basov, Russia silvered ruby rod May 16, 1960! (1915- ) (1921-1999) (1922-2001) USA Developed maser 1954 Suggested laser 1958 (1927-2007) Developed maser 1955 The editor Samuel Goudsmit at Suggested laser 1958 Nobel Prize 1981 Demonstrated Ruby Suggested the Physical Review Letters rejected his Nobel Prize 1964 (for laser spectroscopy) semiconductor laser Laser 1960 Married with Townes article about the first optical maser as 1958 "just another maser paper" and could sister Nobel Prize 1964 T.H. Maiman, “Stimulated Optical Radiation in Ruby,” not be persuaded to change his mind A.L. Schawlow and C. H. Townes Infrared and Optical Nature 187, 493 - 494 (August Masers, Phys. Rev. 112, 1940–1949 1960) Instead a very concise and easy-to- T.H. Maiman, “Stimulated Optical Maiman with a "death-ray weapon" Radiation in Ruby,” Nature 187, 493 - 494 miss 300 word letter was published in as he appeared in the newspapers (August 1960)

Laboratory of Nature in August, 1960 Laboratory of PHOTONICS PHOTONICS

and and MICROWAVE Eng. MICROWAVE Eng. A visionary 50 years prediction 1962 Radio Evolution vs Photonic Evolution How to solve the estimated bandwidth demand 2012 1887 (telephone, video and data) of 50-100 GHz between large 1903 1906 1914 1915 1918 1933 1961 Spark gap cities ? First arc First radio First Super- FM FM stereo Transmitter transmitter broadcast of coherent SSB hetero- modul- Broad- ”A possible alternative, a scheme vaguely reminiscent of with voice and radio modul- dyne ation. casting Alexander Graham Bell’s “Photophone,” has recently On-Off continuos music transmitter ation receiver emerged through the development of a continuously operating keying radio waves Subcarrier AM AM FM gaseous optical maser... A system employing this or some FSK keying other yet-to-be developed type of maser might conceivably be modulation modulation. modulation. used to derive an enormous bandwidth for long distance transmission. The light beam, suitably modulated, would be shielded from outside effects (rain, fog, refraction due to 1962 inhomogeneities) in a gas-filled or evacuated underground First pulsed pipe. The system might comprise a number of repeater semiconductor sections each several hundred miles in length...The over-all laser Estill Green, Executive Vice system bandwidth might be millions or tens of millions of President of Bell Labs megacycles..” Estill I. Green, Communication Spectra by the Wholesale—2012 A.D., Proc. Of the IRE, vol. 50, no. 5, pp. 585–587, May 1962.

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First pulsed semiconductor laser Radio Evolution vs Photonic Evolution

1887 1903 1906 1914 1915 1918 1933 1961 Spark gap First arc First radio First Transmitter transmitter broadcast of coherent SSB Super- FM FM stereo with voice and radio modul- hetero- modul- Broad- continuos music transmitter ation dyne ation. casting On-Off radio waves receiver keying AM AM Subcarrier Schematic diagram of initial concepts FSK keying Holonyaks red (660nm ) modulation modulation. FM for an injection laser developed at Nick Holonyak, GE, GaAsP laser together General Electric Research modulation. with some bulk material USA (1928-) Robert N. Hall, GE, Laboratories by Robert Hall in 1962. First visible GaAsP Laser started working at 12 amperes! USA (1919- ) LED/laser, 1962 1962 1970 The first pulsed laser diode Hall: September 16 Nathan: September 28 First pulsed First CW was demonstrated by Robert Holonyak: October 10 Rediker: October 12 semiconductor semiconductor N. Hall and independently laser laser within a month by three other groups in 1962. Hall's device was made of gallium arsenide and emitted at 850 nm in the near-infrared region of the T. M. Quist, R. H. Rediker, R. J. Keyes, W. E. Krag, B. Lax, A. L. McWhorter, and H. J. Zeiger , spectrum. “Semiconductor maser of GaAs,” Appl. Phys. Lett., 1, pp. 91–92, Dec. 1962.

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and and MICROWAVE Eng. MICROWAVE Eng. First room temperature semiconductor laser diode First Continuous Wave Semiconductor Laser

By using a double heterostructure it was possible to get good carrier and light confinement. Zhores Alferov, Russia (1930- ) Izuo Hayashi, Japan Morton B. Panish Nobel Prize 2000 Minimum threshold current density in (1922- 2005) (1929- ) Alferov´s laser was 1kA/cm 2 at 300K Achieved room temperature operation in double Achieved room temperature operation in double which was a factor 5 better than earlier heterostructure AlGaAs/GaAs laser in May 1970 heterostructure AlGaAs/GaAs laser in June 1970 resuls and made CW operation in room temperature possible.

Today the lasers are about 1 order of magnitude better

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Radio Evolution vs Photonic Evolution First Demonstration of Total Internal Reflection

1962 1970 1970 First pulsed First CW First low loss semiconductor semiconductor optical fiber laser laser

Jean-Daniel Colladon (1802-1893) John Tyndall (1820-1893) Switzerland Great Britain Demonstrated TIR 1841 Demonstrated and investigated TIR 1870

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and and MICROWAVE Eng. MICROWAVE Eng. Light and Image Guiding Systems The low loss optical fiber

Abraham Van Heel, Elias Snitzer Charles K. Kao, Robert D. Maurer, Heinrich Lamm (1899-1966) (1925-2012) (1933-) (1924-) Germany/USA Delft University, American Optical Inc, Standard Telecom. Corning Glass Works, (1908-?) Netherlands USA Laboratories, UK USA . William Wheeler First fiber imaging Developed fiber Theory for single mode Proposed fiber optics for Demonstrated low loss USA bundle 1930 cladding for fiber fiber, 1961 telecom and showed that (17 dB/km) fiber for (1851-1932) The image of a lamp imaging bundles, Demonstrated it could be realized. telecom , 1970 and Invented hollow tubes For "economical generation of filament before and 1953, ~1000dB/km Neodynium glass laser, Made a world tour to sell 4dB/km 1972 with higly reflective light it should be used in great after transmission loss 1961, and erbium glass the idea 1966 F. P. Kapron, D. B. Keck, and R. D. silver coating for a light intensity in one point instead of Maurer, ‘‘Radiation losses in glass optical laser 1965 waveguides,’’ Applied Physics Letters 17 piping system 1880 small intensity in many points." Laboratory of pp. 423–425, Nov.Laboratory 15, 1970,p.of 423. PHOTONICS Nobel Prize 2009 PHOTONICS

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Radio Evolution vs Photonic Evolution First single mode Distributed FeedBack laser

1903 1906 1914 1915 1918 1933 1961 1887 First arc First radio First Spark gap transmitter broadcast of coherent SSB Super- FM FM stereo Transmitter with voice and radio modul- hetero- modul- Broad- continuos music transmitter ation dyne ation. casting On-Off radio waves receiver AM AM Subcarrier keying FSK keying modulation modulation. FM modulation. Herwig Kogelnik, Charles V. Shank, Michiharu Nakamura, Donald R. Scifres (1954 –) (1932 –) (1943 –) Hitachi, Japan 1962 1970 1970 1975 Xerox Research Center, Bell Labs, USA Bell Labs, USA USA First pulsed First CW First low loss First DFB Developed the theory for both index and First optically pumped DFB First electrically pumped semiconductor semiconductor optical fiber singlemode gain coupled DFB lasers and 1973 and first room DFB laser, 1974 laser laser laser demonstrated first DFB laser with a dye temperature CW DFB laser impregnated plastic thin film 1971 . 1975

H. Kogelnik, CV Shank, ”Coupled-Wave Theory of Distributed Feedback Lasers,” Journal of Applied Physics, Vol. 43, No. 5. (1972), pp. 2327-2335

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and and MICROWAVE Eng. MICROWAVE Eng. Radio Evolution vs Photonic Evolution Research on Coherent Optical Receivers

1903 1906 1914 1915 1918 1933 1961 in late 1980´s 1887 First arc First radio First Spark gap transmitter broadcast of coherent SSB Super- FM FM stereo Main motivation was the Transmitter with voice and radio modul- hetero- modul- Broad- improved sensitivity continuos music transmitter ation dyne ation. casting ...but the polarization tracking On-Off radio waves receiver AM AM Subcarrier and frequency/phase locking of keying FSK keying modulation modulation. FM LO were very challenging modulation.

1962 1970 1970 1975 1985-1989 First pulsed First CW First low loss First DFB Research on semiconductor semiconductor optical fiber singlemode coherent laser laser optical laser receivers Polarization insensitive double balanced optical receiver, 1987 L. D. Tzeng, W. L. Emkey, C. A. Jack, and C. A. Bums, “Polarization- insensitive coherent receiver using a double balanced optical hybrid system,” Electron. Lett., vol. 23, no. 22, pp. 1195-1196, Oct. 22, 1987.

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Radio Evolution vs Photonic Evolution The Erbium Doped Fiber Amplifier

1962 1970 1970 1975 1985-1989 1987 Robert J. Mears David N. Payne Emmanuel Desurvire Randy Giles (1961-) (1944-) (1955-) (1955-) First pulsed First CW First low loss First DFB Research on First Erbium- University of Bell Labs, USA Bell Labs, USA semiconductor semiconductor optical fiber singlemode coherent doped Fiber University of Southhampton, Southhampton , laser laser laser optical Amplifier UK receivers UK R. J. Mears, L. Reekie, I. M. Jauncey, and D. N. Payne, "High-gain rare-earth- E. Desurvire, J. R. Simpson, and P. C. Becker, “High- doped fiber amplifier at 1.54 μm," in Optical Fiber Communication, 1987 OSA gain erbium doped traveling wave fiber amplifier”, Technical Digest Series (Optical Society of America, 1987), paper WI2. Opt. Lett. 12 (11), 888 (1987)

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and and MICROWAVE Eng. MICROWAVE Eng. Radio Evolution vs Photonic Evolution

1962 1970 1970 1975 1985-1989 1987 First pulsed First CW First low loss First DFB Research on First Erbium- semiconductor semiconductor optical fiber singlemode coherent doped Fiber laser laser laser optical Amplifier receivers Most deployed fiber-optic systems for telecom still utilize simple on- off keying and direct detection (Morse code and crystal receiver)

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Increased Capacity Demand 112 Gb/s Complete On-off-keying ETDM System from Internet Video Transmitter made by KTH+Syntune+Svedice

...and 2019: 168 exabytes per Successful 42 km transmission month (518Tbit/s) over dispersion compensated fiber Upgrade to 100 Gbit/s per WDM in ground demonstrated by channel is needed! ACREO+KTH 2010

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and and MICROWAVE Eng. MICROWAVE Eng. The problem: fiber dispersion Radio systems today are the future for photonics

Different wavelength components travel with different velocity 1991 1991 1994 1995 1998 1998 2001

GSM WiFi GPS DVBS ADSL DVBT UMTS (3G )

GMSK OFDM or CDMA QPSK DMT OFDM W-CDMA CCK with QAM Gaussian Code Quadrature Discrete Minimum Orthogonal Division phase shift multitone Dispersive fiber Shift frequency-division Multiple keying Keying multiplexing Access

Distance ∝∝∝ 1/(Bitrate) 2 Adaptive dispersion 10 Gbit/s: 65 km compensation needed but Next generation optical transmission systems will be 40 Gbit/s: 4 km still difficult to reach e.g. 65 advanced digital radio systems at optical frequencies 100 Gbit/s: 650 m! km with 100 Gbit/s! The solution? Laboratory of Laboratory of PHOTONICS PHOTONICS

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Why advanced modulation formats? Higher spectral efficiency! ( lower modulation bandwidth for same bitrate )

DQPSK, QPSK, QAM, OFDM, SCM, SSB...

•Better tolerance to fiber dispersion

•More wavelength channels per fiber (or higher bitrate for same channel grid)

•Lower bandwidth demands of electronics and photonics

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