Abstract: A system and method is provided for minimizing power fluctuations and crosstalk in a wavelength division multiplexed optical (WDM) network employing dynamic add/drop techniques by utilizing amplifiers operating in a nearly linear region. Conventionally, erbium-doped fiber amplifiers (EDFAs) are operated in saturation for providing signal amplification in a WDM network. Instead of using saturated EDFAs, the present invention includes optical amplifiers operated in a linear or nearly linear regime for providing signal amplification in a dynamic add/drop or bursty data WDM network. By operating optical amplifiers in a linear or nearly linear regime, power fluctuations, transients and crosstalk caused by adding/dropping or switching channels in the WDM network are minimized. Raman amplifiers, EDFAs, or semiconductor optical amplifiers (SOAs) can all be operated in a linear or nearly linear range to provide linear amplification in such a dynamic add/drop or bursty data WDM network.

Abstract: A system and method is provided for minimizing power fluctuations and crosstalk in a wavelength division multiplexed optical (WDM) network employing dynamic add/drop techniques by utilizing amplifiers operating in a nearly linear region. Conventionally, erbium-doped fiber amplifiers (EDFAs) are operated in saturation for providing signal amplification in a WDM network. Instead of using saturated EDFAs, the present invention includes optical amplifiers operated in a linear or nearly linear regime for providing signal amplification in a dynamic add/drop or bursty data WDM network. By operating optical amplifiers in a linear or nearly linear regime, power fluctuations, transients and crosstalk caused by adding/dropping or switching channels in the WDM network are minimized. Raman amplifiers, EDFAs, or semiconductor optical amplifiers (SOAs) can all be operated in a linear or nearly linear range to provide linear amplification in such a dynamic add/drop or bursty data WDM network.

Abstract: A wavelength converter incorporating an on-chip integrated laser for use in an optical system. The converter includes a first port for receiving an optical input signal such as a WDM signal and providing it to an interferometer, and an output port for outputting a signal which is a wavelength-converted version of the input signal. An optical source or laser is fabricated on the chip substrate on which the interferometer is formed for providing operating power to the interferometer. Power levels of the input signal are maintained by adjusting an on-chip semiconductor optical amplifier that receives the optical input signal and provides the amplified signal to the interferometer. In an alternative embodiment, the on-chip optical source is replaced by an on-chip pre-amplifier for an external laser source.

Abstract: An optical network comprising a broad band optical source having a temporal characteristic and an optical wavelength conversion apparatus. The optical wavelength conversion apparatus comprising a laser means for producing a narrow band optical spectrum signal, a means for receiving a broad band optical signal having a temporal characteristic, and a spectral compactor means. The spectral compactor means is responsive to the narrow band optical spectrum signal and the broad band optical signal, for modulating the narrow band optical signal with the temporal characteristic of the broad band optical signal.

Abstract: A single-port, reflective, optical modulator with internal amplification. In one advantageous embodiment of the present invention, the single-port modulator includes a semiconductor waveguide amplifier with a high reflector at one end. The single-port geometry reduces the high packaging cost associated with two-port modulators, while the internal amplification compensates for splitting and coupling losses. The single-port optical modulator generally includes an input/output port for receiving a light input signal. A modulation region for modulating the light input signal in response to an electrical drive signal is included along with an amplification region for providing amplification of the light input signal. The modulation region and the amplification region include a waveguide for directing the light input signal.

Abstract: A method and apparatus for wavelength shifting an intensity-modulated optical signal are provided. The present invention utilizes an intensity-modulated first optical signal at a first wavelength, a second optical signal at a second wavelength and an optical amplifier with a gain which varies with the intensity modulation of the first optical signal. The optical amplifier receives and amplifies the first and second signals such that variations in the intensity modulation of the first optical signal alter the optical amplifier gain, producing an amplified second optical signal with corresponding intensity variations. In accordance with the invention the power level of the second optical signal is adjusted to reduce the amplifier gain recovery time and thereby reduce the rise time of the intensity variations of the amplified second optical signal. Optical wavelength shifting by amplifier gain compression is thereby made possible at bit rates of 10 Gbits/sec or higher.

Abstract: The present invention provides an apparatus and method for performing polarization-insensitive four-photon mixing of optical signals. The polarization-insensitive optical mixer includes a polarization splitter for splitting an optical signal into parallel and perpendicular polarization components, different mixing paths for mixing a pump signal of like polarization with each of the parallel and perpendicular components in a nonlinear mixing device, and a polarization combiner for combining the resulting mixing products. Certain of the mixing products represent phase conjugates of the input optical signal, and are therefore useful in compensating for chromatic distortion in optical fiber.

Abstract: An improved semiconductor optical amplifier with shortened gain-recovery time is disclosed. In the inventive device a carrier-storage region is placed adjacent to the gain region of the amplifier. Passage of carriers from the storage region to the gain region rapidly replenishes the carrier population within the gain region, thereby permitting rapid recovery of the amplifier gain.