Abstract: A new method and apparatus provide efficient highly non-degenerate four-wave mixing (FWM) signal in a semiconductor quantum well microcavity device. The phase mismatch between beam incidence angle and microcavity resonance frequency is minimized by using obliquely incident pump and probe beams. The FWM device is used to implement a wavelength multiplexer, a demultiplexer, a packet wavelength multiplexer, a packet demultiplexer, a time division multiplexer, a time division demultiplexer, a wavelength converter, and a wavelength switch.

Abstract: A method for launching a high-power signal into anomalous-dispersion fiber without suffering excess spectral broadening and waveform distortion. A high-power signal is launched as very short optical solitons, typically with a pulse width of approximately 1 to 10 ps. The pulse width of the solitons will broaden adiabatically (or nearly adiabatically) as they propagate down the anomalous-dispersion fiber as the average power of the soliton decreases. At the same time, the optical spectrum will narrow. After some distance of travel, when the width of the pulses have broadened to a suitable duration and the average power has decreased to a point where penalties from nonlinearities are insignificant, the pulses enter a significantly linear propagation regime with first order dispersion near zero. A dispersion-shifted fiber may be used or any additional dispersion can be compensated at the receiver. Consequently, no further significant broadening of the spectrum occurs when the signal is received at the receiver.

Abstract: An apparatus for, and method of, decreasing a temporal duration of an optical input pulse having an input power spectrum associated therewith, the apparatus and method operative on at least unchirped optical input pulses. The apparatus comprises: (1) a zero-dispersion pulse shaper for receiving the optical input pulse and spectrally spreading the input pulse to produce a spectrally-spread pulse and (2) a modulator array interposed within the zero-dispersion pulse shaper for receiving the spectrally-spread pulse and selectively attenuating a portion of the power spectrum of the spectrally-spread pulse by a predetermined amount to produce a selectively-attenuated spectrally-spread pulse, the zero-dispersion pulse shaper focusing and recombining the selectively-attenuated spectrally-spread pulse to produce an output pulse having a broader power spectrum than the input pulse, the output pulse further having a temporal duration less than the input pulse, regardless of whether the input pulse is chirped.

Abstract: An optical image processor includes a nonlinear active gain medium for recording an interference pattern that corresponds to the Fourier transform of an input image or the multiplicative product of the Fourier transforms of two respective input images.

Abstract: An optical polarization rotator is developed for use with infrared radiation using a nonlinear, two-photon interaction in a solid medium. The mechanism employed is resonance dispersion, where the sum frequency of an infrared beam to be rotated and a visible control beam is close to the frequency of a two-photon transition of exciton states, thereby producing different amounts of dispersion for the two orthogonal components of the linearly polarized infrared beam. The result of a phase difference between the two components is a rotation of the plane of polarization of the infrared beam.