In-line fiber optic memory

Patent

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

350 9616, G02B 5172

Patent

active

047385030

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 a 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 a standard coupler with a pump signal modulation technique. The pump signal is input to the loop as a series of pulses having a duration and a periodicity chosen to prevent overlap of recirculating pump pulses with input pump pulses until at least two circulations of the loop, which minimizes pump power fluctuations and will therefore enhance output signal stability.

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 (1985-07-01), Stokes et al.
patent: 4536058 (1985-08-01), 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", J. of Lightwave Technology, vol. LT-3, No. 4, 8/85, pp. 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.
Tur et al., "Laser Phase Noise Effects in Fiber Optic Signal Processors with Recirculating Loops", Conference on Lasers and Electro-Optics, 1983.
Tur et al., "Phase Noise Effects in Recirculating Delay Lines Driven by Semiconductor Lasers", OFC, 1983.
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 Quntum Electronics, vol. QE-18, No. 10, Oct. 1979, pp. 1157-1160.
Bergh, et al., "Single-Mode Fiber Optic Directional Coupler," Electroics Letters, vol. 16, No. 7, Mar. 27, 1980, pp. 260-261.
Ikeda, M., "Stimulated Raman Amplification Characteristics in Long Span Single-Mode Silica Fibers," Optics Communications, vol. 39, No. 3, Oct. 1, 1981, pp. 148-152.
S. A Newton, et al., "Single Mode Fiber Recirculating Delay Line," SPIE Conference, Jan. 1982, paper 325-21 (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.
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.
L. F. Stokes, et al., "All-Single-Mode Fiber Resonator," Optics Letters, vol. 7, No. 6, Jun. 1982, pp. 288-290.
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.
Koepf, et al., "Raman Amplification at 1.118 .mu.m in Single-Mode Fibre and Its Limitation by Brillouin Scattering,"Electronics Letters, vol. 18, No. 22, Oct. 28, 1982, pp. 942-943.
Ohashi, et al., "Phase-Matched Light Amplification by Three-Wave Mixing Process in a Birefringent Fiber due to Externally Applied Stress," Applied Physics Letters, vol. 41, No. 12, Dec. 15, 1982, pp. 1111-1113.
M. Tur, et al., "Spectral Structure of Phase-Induce 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 Letters, 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.
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.
A. R. Chraplyvy, et al., "Synchronously Pumped D.sub.2 Ga-In-Glass Fiber Raman Laser Operating at 1.56 .mu.m," Optics Letters, vol. 9, No. 6, Jun. 1984, pp. 241-242.
Pocholle, et al., "Nonlinear Optical Amplification in Single-Mode Fibers: Potential Applications to Optical Communications Systems," Conference on Lasers and Electro Optics, paper FR1, Jun. 22, 1984.
M. Nakazawa, "Optical Amplification by Raman Effect in Silica Fiber," Conference on Lasers and Electro Optics, paper FR2, Jun. 22, 1984.
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-Diode-Pumped Nd:YAG Laser," Optics Letters, vol. 10, No. 2, Feb. 1985, pp. 62-64.
Desurvire, et al., "Raman Amplification of Recirculating Pulses in a Reentrant Fiber Loop," Optics Letters, vol. 10, No. 2, Feb. 1985, pp. 83-85.
Moshe Tur, et al., "Theory of Laser Phase Noise in Recirculating Fiber-Optic Delay Lines," IEEE Journal of Lightwave Technology, vol. LT-3, No. 1, Feb. 1985, pp. 333-342.
E. Desurvire, et al., "Raman Amplification in a Single-Mode Reentrant Fiber Loop," presented at the Third International Conference on Optical Fiber Sensors, Feb. 13-14, 1985, San Diego, California, paper WBB5.
Masataka Nakazawa, "Synchronously Pumped Fiber Raman Gyroscope," Optics Letters, vol. 10, No. 4, Apr. 1985, pp. 193-195.
J. P. Pocholle, et al., "Raman and Four Photon Mixing Amplification in Single Mode Fibers," Optical Engineering, vol. 24, No. 4, Jul./Aug. 1985, pp. 600-608.
W. V. Sorin, et al., "Single-Mode-Fiber Ring Dye Laser," Optics Letters, vol. 10, No. 11, Nov. 1985, pp. 550-552.
M. J. F. Digonnet, et al., "Theoretical Analysis of Optical Fiber Laser Amplifiers and Oscillators," Applied Optics, vol. 24, No. 3, Feb. 1, 1985, pp. 333-342.
"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.

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

In-line fiber optic memory does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with In-line fiber optic memory, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and In-line fiber optic memory will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-2171687

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.