Broadband optical amplification system

Details Broadband optical amplification system Broadband optical amplification system

1999-01-15

2001-10-16

Moskowitz, Nelson (Department: 3662)

Optical: systems and elements

Optical amplifier

Raman or brillouin process

C359S199200, C359S341320, C372S003000

Reexamination Certificate

active

06304368

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a system for broadband optical amplification, particularly to a dual window Raman amplifier, and more particularly to a dual window, bi-directional Raman amplifier.
2. Description of the Prior Art
Currently, dense wavelength division multiplexing (DWDM) technology is being used to dramatically improve high capacity optical transmission systems. Systems are now being developed that will allow transmission of 64 (and beyond) WDM channels on a single fiber. This represents a dramatic increase from existing 16 channel systems.
Broadband optical amplifiers will be essential components in such systems and will need to provide high enough bandwidth, low enough noise, and sufficient power to minimize channel crosstalk and degradation due to fiber nonlinearities. In addition, it is important that the amplifiers provide a graceful upgrade path for the customer. It is very likely that customers initially will only require a fraction of the maximum system capacity, while maintaining the option to expand the capacity at a later point. More specifically, they will require amplifiers that can be upgraded (as opposed to being replaced) to the full system capacity at a small additional cost.
Recently, it has been demonstrated that the bandwidth of erbium doped fiber amplifiers (operating around 1550 nm) can be expanded to more than 80 nm using a split band technique. Such amplifiers would easily accommodate 100 wavelength channels at 100 GHz spacing. However, current systems where the wavelength channels occupy a large contiguous bandwidth have the significant disadvantage that they suffer substantial penalties due to stimulated Raman scattering. These penalties occur because the lower wavelength channels loose power (and thereby signal to noise ratio) as they pump the upper wavelength channels. Also, an erbium doped fiber amplifier with the full 80 nm bandwidth may not necessarily provide the customer with the desired upgrade path.
SUMMARY OF THE INVENTION
Thus an optical communication system is needed which can achieve the benefits of broadband DWDM, while reducing penalties due to stimulated Raman scattering. Accordingly, the present invention is directed to a system of amplification in which signal gain is provided in independent wavelength windows.
The present invention includes an optical communication system and optical signal amplifier for amplifying an optical signal having at least a first and a second wavelength as it propagates therethrough. The optical signal amplifier includes an input port; an output port; an optical medium, wherein a portion of the optical medium comprises a plurality of optical paths corresponding to the first and second wavelengths of the optical signal; a light radiation generator capable of coupling light radiation of a plurality of light radiation wavelengths related to the first and second wavelengths of the optical signal into each of the optical paths, whereby the first and said second wavelengths are amplified by Raman amplification; and an optical combiner for recombining the first and second wavelengths of the optical signal to generate the amplified optical signal.
The present invention may further include an optical signal direction selective device disposed in each of the optical paths for reducing scattering of the optical signal, and a bypass medium for allowing the light radiation to bypass the optical signal direction selective device. The light radiation generator may include a light pump, a light isolator, a light cavity and gratings, at least one wavelength division multiplexor, and a plurality of light couplers. The present invention may also include gain flattening components, dispersion compensating components, an optical signal attenuator, and an optical bypass switch for controllably removing one or more of the first or second wavelengths from the optical signal. The present invention may also be configured for bidirectional operation.


REFERENCES:
patent: 3346741 (1967-10-01), Mayer et al.
patent: 4922481 (1990-05-01), Hicks
patent: 4923291 (1990-05-01), Edagawa et al.
patent: 5452116 (1995-09-01), Kirkby et al.
patent: 5623508 (1997-04-01), Grubb et al.
patent: 5959750 (1999-09-01), Eskildsen et al.
Nielsen et al, IEEE Photaries Techn. Lett., vol. 10, #10, 1492-4; abstract and herewith, Oct. 1998.*
Hansen et al, OSA Trends in optics photon., vol. 5, pp. 12-15. abstract only, Jul. 13, 1996.*
Eschildsen et al, OSA Trends in Optics Photon vol. 5, pp. 306-8; abstract only herewith, Jul. 13, 1996.*
Stentz et al, OFC '96, Opt. Fiber Commun., vol. 2, pp. 391-4, Mar. 1, 1996.*
Stenz et al, OFC '96, Opt. Fiber Communic., vol. 2, pp. 16-17, Mar. 1, 1996.*
Hansen, P.B. and Eskildsen, L., “Remote Amplification in Repeaterless Transmission Systems”, Optical Fiber Technology, 3, 221-237 (1997).
Stentz, A.J., “The Revival of Raman Amplifiers” Proceedings of the 1996, 9th Annual Meeting of IEEE Lasers and Electro-Optics Society, LEOS'96. Part 1 (of2), 1996.
Riishoj, J, Nielsen, T.N., and Gliese, U., “A 4 Gb/s 2-Level to 2 Gsymbol/s 4-Level Converter GaAs IC Semiconductor Optical Amplifier QPSK Modulators”, IEE Journal of Solid-State Circuits, vol. 29, No. 10, pp. 1277-1281, Oct. 1994.
Hansen, et al., “Repetition-Rate Dependence of Gain Compression in InGaAsP Optical Amplifiers Using Picosecond Optical Pulses”, IEE Journal of Quantum Electronics, vol. 25, No. 12, pp. 2611-2620, Dec. 1989.
Joergensen et al., “All-Optical Wavelength Conversion at Bit Rates Above 10Gb/s Using Semiconductor Optical Amplifiers”, IEEE Journal of Selected Topics in Quantum Electronics, vol. 3, No. 5, pp. 1168-1180, Oct. 1997.
Hansen, et al., “442km repeaterless transmission in 10Gbit/s system experiment,” Electronics Letters, vol. 32, No. 11, pp. 1018-1019, May 23rd, 1996.
Eskilden, et al., “Single fibre repeaterless transmission over 490km at 2.488Gbit/s using a remote preamplifier and dispersion compensation”, Electronics Letters, vol. 32, No. 18, pp. 1696-1697, Aug. 29th, 1996.
Hansen et al., “High sensitivity 1.3um optically preamplified receiver using Raman amplification”, Electronics Letters, vol. 32, No. 23, pp. 2164-2165, Nov. 7th, 1996.
Hansen et al., “5.29km unrepeatered transmission at 2.488GBit/s using dispersion compensation, forward error correction, and remote post-and pre-amplifiers by diode-pumped Raman lasers”, Electronics Letters, vol. 31, No. 17, 1460-1461, Aug. 17th, 1995.
Eskildsen, et al., “Remote postamplifiers in repeaterless transmission systems,” Electronic Letters, vol. 31, No. 14, pp. 1163-1164, Jul. 6th, 1995.
Hansen, et al., “2.488Gbit/s unrepeatered transmission over 423km employing remotely pumped post-and preamplifiers”, Electronics Letters, vol. 31, No. 6, pp. 466-467, Mar. 16th, 1995.
Heismann et al., “Automatic polarisation demultiplexer for polarisation-multiplexed transmission systems”, Electronics Letters, vol. 29, No. 22,1965-1966, Oct. 28th, 1993.
Hansen, et al., “Optical Demultiplexing at 6 Gb/s Using a Semiconductor Laser Amplifier as an Optical Gate”, IEEE Transactions Photonics Technology Letters, vol. 3, No. 11, pp. 1018-1020, Nov. 1991.
Hansen, et al., “374-km Transmission in a 2.5-Gb/s Repeaterless System Employing a Remotely Pumped Erbium-Doped Fiber Amplifier”, IEEE Photonics Technology Letters, vol. 7, No. 5, pp. 588-590, May 1995.
Silva, et al., “Remotely Pumped Erbium-Doped Fiber Amplifiers for Repeaterless Submarine Systems”, IEEE Photonics Technology Letters, vol. 7, No. 9, pp. 1081-1083, Sep. 1995.
Hansen, et al., “Unrepeatered WDM Transmission Experiment with 8 Channels of 8 Gb/s Over 352 km”, IEEE Photonics Technology Letters, vol. 8, No. 8,pp. 1082-1084, Aug. 1996.
Hansen, et al., “Capacity Upgrades of Transmission Systems by Raman Amplification”, IEEE Photonics Technology Letters, vol. 9, No. 2, pp. 262-264, Feb. 1997.
Danielsen, et al., “All Optical Wavelength Conversion Schemes for Increased Input Power Dynamic Range”, IEEE Photonics Technology Letters, vol. 10, No. 1, pp. 60-62, Jan. 1998.
Hansen, et al.,

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