Optical: systems and elements – Optical modulator – Light wave temporal modulation
Patent
1992-02-26
1994-09-13
Moskowitz, Nelson
Optical: systems and elements
Optical modulator
Light wave temporal modulation
359183, 372 18, 372 95, G03H 102, G08B 523, H01S 310
Patent
active
053473922
ABSTRACT:
An electro-optic resonant cavity is used to achieve phase modulation with lower driving voltages. Laser damage thresholds are inherently higher than with previously used integrated optics due to the utilization of bulk optics. Phase modulation is achieved at higher speeds with lower driving voltages than previously obtained with non-resonant electro-optic phase modulators. The instant scheme uses a data locking dither approach as opposed to the conventional sinusoidal locking schemes. In accordance with a disclosed embodiment, a resonant cavity modulator has been designed to operate at a data rate in excess of 100 Mbps. By carefully choosing the cavity finesse and its dimension, it is possible to control the pulse switching time to within 4 ns and to limit the required switching voltage to within 10 V. Experimentally, the resonant cavity can be maintained on resonance with respect to the input laser signal by monitoring the fluctuation of output intensity as the cavity is switched. This cavity locking scheme can be applied by using only the random data sequence, and without the need of additional dithering of the cavity. Compared to waveguide modulators, the resonant cavity has a comparable modulating voltage requirement. Because of its bulk geometry, resonant cavity modulator has the potential of accommodating higher throughput power. Furthermore, mode matching into a bulk device is easier and typically can be achieved with higher efficiency. On the other hand, unlike waveguide modulators which are essentially traveling wave devices, the resonant cavity modulator requires that the cavity be maintained in resonance with respect to the incoming laser signal. An additional control loop is incorporated into the modulator to maintain the cavity on resonance.
REFERENCES:
patent: 2385085 (1945-09-01), Labin
patent: 3512870 (1970-05-01), Wilson et al.
patent: 4289403 (1981-09-01), Allington
patent: 4742576 (1988-05-01), McMahon
patent: 4925302 (1990-05-01), Cutler
patent: 4998255 (1991-03-01), Gerstenberger et al.
Travelling-Wave Electrooptic Modulator by C. M. Gee, G. D. Thurmond and H. W. Yen, Appl. Opt., vol. 22, No. 13, pp. 2034-2037, Jul. 1983.
Thin-Film LiNbO.sub.3 Electro-Optic Light Modulator by I. P. Kaminow, J. R. Carruthers, E. H. Turner and L. W. Stulz, Appl. Phys. Lett., vol. 22, No. 10, pp. 540-542, May 1973.
Resonant Cavity Sensor for Integrated Optics by R. R. A. Syms, IEEE Journal Of Quantum Electronics, vol. QE-21, No. 4, Apr. 1985.
Resonant Modulation by W. J. Stewart, I. Bennion and M. J. Goodwin, Phil. Trans. R. Soc. Lond. A313, p. 401, 1984.
Electro-Optic Resonant Waveguide Modulation by W. J. Stewart, I. Bennion and M. J. Goodwin, Tenth European Conference On Optical Communication, Sep. 1984.
Design, Construction, and Analysis of an Ultra-Low Expansion Quartz Resonant Cavity Passive Ring Resonator Laser Gyroscope by K. A. Pugh, Master Of Science Thesis, Air Force Institute of Technology Air University, Mar. 1982.
Coherent Communication Link Using Diode-Pumped Lasers by T. J. Kane and R. W. Wallace, Final Report For Contract NAS5-30487 for NASA Goddard Space Flight Center, Aug. 1989.
Optical Waves in Crystals by A. Yariv, John Wiley and Sons, Inc., New York, 1984.
An Interferometer Useful for Pulse Compression of a Frequency Modulated Light Source by F. Gires and P. Tournois, C.R. Acad. Sci., vol. 258, p. 6112, 1964.
Laser Frequency Stabilization by Polarization Spectroscopy of a Reflecting Reference Cavity by T. W. Hansch and B. Couillaud, Optical Communications, vol. 35, No. 3, Dec. 1980.
Laser Phase and Frequency Stabilization Using an Optical Resonator by R. W. P. Drever, J. L. Hall, F. V. Kowalski, J. Hough, G. M. Ford, A. J. Munley and H. Ward, Appl. Physl B, vol. 31, pp. 97-105, 1983.
Principles of Resonant Cavity Optical Modulator by T. F. Gallagher, N. H. Tran and J. P. Watjen, Appl. Opt., vol. 25, No. 4, pp. 510-514, Feb. 1986.
Broadband Optical Coupling Modulation by F. R. Nash and P. W. Smith, IEEE J. Quantum Electron., vol. AE-4, pp. 26-34, 1968.
Optical Coupling Modulation in Travelling-Wave Cavities by D. M. Henderson and V. A. Vilnrotter, Appl. Phys. Lett., vol. 30, No. 7, pp. 335-337, Apr. 1977.
Robinson et al; Proc. SPIE, Free Space Laser Comm. Tech. III; L.A., Calif., Jan. 21-22, 1991; vol. 1417, pp. 421-430.
Robinson, D. L.; Telecomm. and Data Acquis. Report, pp. 240-247, NTIS N 89-27871/7; abst. only provided herewith.
Robinson et al; Opt Eng., vol. 32, #3, pp. 458-463, Mar. 1993; abst only provided herewith.
Chen et al; Proc. SPIE, vol. 1635, pp. 135-143, 1992 abst only provided herewith.
Chen Chien-Chung
Hemmati Hamid
Robinson Deborah L.
Jones Thomas H.
Kusmiss John H.
Miller Guy M.
Moskowitz Nelson
The United States of America as represented by the Administrator
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