1985-02-08
1987-11-24
LaRoche, Eugene R.
350 9616, G02B 5172
Patent
active
047084219
ABSTRACT:
A fiber optic recirculating memory comprises a splice-free length of optical fiber which forms a loop that is optically closed by means of a fiber optic coupler. The coupler couples an optical signal input pulse to the loop for circulation therein, and outputs a portion of the signal pulse on each circulation to provide a series of output pulses. A pump source is included to pump the fiber loop with a pump signal having sufficient intensity to cause stimulated Raman scattering in the fiber loop, and thereby cause amplification of the circulating signal pulse. The fiber characteristics, coupler characteristics, and pump power are selected to yield a Raman gain which compensates for the total round-trip losses in the fiber loop, so as to provide an output pulse train of constant amplitude pulses. The invention may be implemented utilizing either a standard coupler or a multiplexing coupler. The multiplexing coupler advantageously permits independent selection of the coupling ratios for the pump signal and signal pulse, thereby allowing these coupling ratios to be selected for minimum loop loss and maximum pumping efficiency.
REFERENCES:
patent: 4136929 (1979-01-01), Suzaki
patent: 4401364 (1983-08-01), Mochizuki
patent: 4469397 (1984-09-01), Shaw et al.
patent: 4473270 (1984-09-01), Shaw
patent: 4493528 (1985-01-01), Shaw et al.
patent: 4530097 (1985-08-01), Stokes et al.
patent: 4536058 (1985-07-01), Shaw et al.
patent: 4556279 (1985-12-01), Shaw et al.
R. H. Stolen, "Fiber Raman Lasers", Fiber and Integrated Optics, vol. 3, No. 1, 1980.
R. H. Stolen, "Active Fibers", New Directions in Guided Wave and Coherent Optics, vol. 1, Martinus Nijhoff Publishers, Boston, 1984.
R. G. Smith, "Optical Power Handling . . . Brillouin Scattering, Applied Optics, vol. 11, No. 11, Nov. 1972, pp. 2489-2494.
Dakss et al., "Amplified Spontaneous Raman Scattering and Gain in Fiber Raman Amplifiers", Journal of Lightwave Technology, vol. LT-3, No. 4, 8/85,806-813.
D. Cotter, "Observation of Stimulated Brillouin Scattering . . . , Electronic Letters, vol. 18, No. 12, pp. 495-496, 1982.
Aoki et al., "Bit Error Rate Evaluation of Optical . . . in an Optical Fibre", Electronics Letters, vol. 21, No. 5, Feb. 28, 1985, pp. 191-193.
Mollenauer et al., "Experimental Demonstration of Soliton . . . by Raman Gain", Optics Letters, vol. 10, No. 5, May 1985, pp. 229-231.
"Phase-Matched Light Amplification by Three Wave Mixing Process in a Birefringent Fiber Due to Externally Applied Stress" Ohashi et al., Applied Physics Letters, Dec. 15, 1982, pp. 1111-1113.
Chinlon Lin, et al., "A Tunable 1.1 .mu.m fiber Raman Oscillator," Applied Physics Letters, vol. 31, No. 2, Jul. 15, 1977, pp. 97-99.
John Auyeung, et al., "Spontaneous and Stimulated Raman Scattering in Long Low Loss Fibers," IEEE Journal of Quantum Electronics, vol. QE-14, No. 5, May 1978, pp. 347-352.
R. H. Stolen, et al., "A Fiber Raman Ring Laser," IEEE Journal of Quantum Electronics, vol. QE-14, No. 11, Nov. 1978, pp. 860-862.
Rogers H. Stolen, "Polarization Effects in Fiber Raman and Brillouin Lasers," IEEE Journal of Quantum Electronics, vol. QE-18, No. 10, Oct. 1979, pp. 1157-1160.
S. A. Newton, et al., "Single Mode Fiber Recirculating Delay Line," SPIE Conference, Jan. 1982, paper 326-21 (8 pages).
J. E. Bowers, et al., "Filter Response of Single-Mode Fibre Recirculating Delay Lines," Electronics Letters, vol. 18, No. 3, Feb. 4, 1982, pp. 110-111.
L. F. Stokes, et al., "All-Single Mode Fiber Resonator," Optics Letters, vol. 7, No. 6, Jun. 1982, pp. 288-290.
M. Tur, et al., "Spectral Structure of Phase-Induced Intensity Noise in Recirculating Delay Lines," SPIE, 1983.
Michel Digonnet, et al., "Wavelength Multiplexing in Single-Mode Fiber Couplers," Applied Optics, vol. 22, No. 3, Feb. 1, 1983, pp. 484-491.
S. A. Newton, et al., "High-Speed Pulse-Train Generation Using Single-Mode-Fibre Recirculating Delay Lines," Electronics Letter, vol. 19, No. 19, Sep. 15, 1983, pp. 756-758.
L. F. Mollenauer, et al., "The Soliton Laser," Optics Letters, vol. 9, No. 1, Jan. 1984, pp. 13-15.
A. R. Chraplyvy, et al., "Synchronously Pumped D.sub.2 Gas-in-Glass Fiber Raman Laser Operating at 1.56 .mu.m," Optics Letters, vol. 9, No. 6, Jun. 1984, pp. 241-242.
R. H. Stolen, et al., "Development of the Stimulated Raman Spectrum in Single-Mode Silica Fibers," Journal of the Optical Society of America B, vol. 1, No. 4, Aug. 1984, pp. 652-657.
Bingkun Zhou, et al., "Efficient, Frequency-Stable Laser-Dode-Pumped Nd:YAG Laser," Optics Letters, vol. 10, No. 2, Feb. 1985, pp. 62-64.
Masataka Nakazawa, "Synchronously Pumped Fiber Raman Gyroscope," Optics Letters, vol. 10, No. 4, Apr. 1985, pp. 193-195.
"Raman Oscillation in Glass Optical Waveguide", Stolen, et al., Applied Physics Letters, vol. 20, No. 2, Jan. 15, 1972, pp. 62-64.
"Low-Threshold cw Raman Laser", Hill, et al., Applied Physics Letters, vol. 29, No. 3, Aug. 1, 1976, pp. 181-183.
"Fiber Raman Lasers", Stolen, NATO Summer Inst. on Fiber and Integrated Optics, Cargese, France, Jun. 1978, pp. 1-17.
Bergh, et al., "Single-Mode Fiber Optic Directional Coupler", Electronics Letters, vol. 16, No. 7, Mar. 27, 1980, pp. 260-261.
Digonnet, et al., "Analysis of a Tunable Single Mode Optical Fiber Coupler", IEEE Journal of Quantum Electronics, vol. QE-18, No. 4, Apr. 1982, pp. 746-753.
Nakazawa, et al., "Active Transmission Line: Light Amplification by Backward-Stimulated Raman Scattering in Polarization-Maintaining Optical Fiber", Journal Optical Society of America, B/vol. 1, No. 1, Mar. 1984, pp. 80-85.
Koepf, et al., "Raman Amplification at 1.118 .mu.m in Single-Mode Fibre and its Limitation by Brillouin Scattering", Electronics Letter, vol. 18, No. 22, Oct. 28, 1982, pp. 942-943.
Ikeda, M., "Stimulated Raman Amplification Characteristics in Long Span Single-Mode Silica Fibers", Optics Communications, vol. 39, No. 3, pp. 148-152.
Pocholle, et al.,"Nonlinear Optical Amplification in Single-Mode Fibers: Potential Applications to Optical Communication Systems", Conference on Lasers and Electro Optics, Jun. 22, 1984.
M. Nakazawa, "Optical Amplification by Raman Effect in Silica Fiber", Conference on Lasers and Electro Optics, Jun. 22, 1984.
L. F. Stokes, et al., "All-Fiber Stimulated Brillouin Ring Laser with Submilliwatt Pump Threshold; Optics Letters, vol. 7, No. 10, Oct. 1982, pp. 509-511.
Desurvire Emmanuel
Digonnet Michel J. F.
Shaw H. J.
LaRoche Eugene R.
Mottola Steven J.
The Board of Trustees of the Leland Stanford Junior University
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