Bell Telephone Laboratories

Lucent Technologies Inc.

At&t Bell Laboratories

At+t Corp.

Agere Systems Optoelectronics Guardian Corp.

Theodoor Charlouis Damen

Michel A Duguay

Van-Tran Nguyen

Masahiro Tsuchiya

David A Miller

Martin C Nuss

Thomas Huntington Wood

Lawrence David Jackel

Richard E Howard

Per Bang Hansen

Julian Stone

Rogers H Stolen

Arthur C Gossard

Daniel S Chemla

Chandra K Patel

Tao-Yuan Chang

Herman Anton Haus

Erich Gornik

Michael A Duguay

William J Skocpol

Jagdeep Shah

Hailin Wang

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.

Wavelength add-drop multiplexing using four-wave-mixing

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. Additionally, the initial wide spectrum of the solitons will result in a high stimulated Brillouin scattering (SBS) threshold reducing the need for artificial broadening of the spectrum.

Applications of solitons in transmission systems employing high launch

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.

Apparatus and method for femtosecond pulse compression based on

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.

Optical image processor employing a nonlinear medium with active gain

In accordance with the present invention, a surface emitting laser includes a substrate, a first distributed feedback mirror formed on the substrate, and an active gain medium formed on the first mirror. The active gain medium includes at least one active, optically emitting layer and one barrier layer. A second distributed feedback mirror is formed on the active gain medium. The first and second mirrors define a resonant cavity for supporting a standing wave optical field at a designed wavelength of operation The first and second mirrors have first and second reflective bandwidths that respectively include first and second transmissive bandwidths for receiving optical pumping energy. The first and second reflective bandwidths are shifted in wavelength relative to one another so that the first and second transmissive bandwidths are located at distinct wavelengths.

Surface emitting laser having improved pumping efficiency

A read/write system which reduces access time in optical disc apparatus is disclosed. The head includes an array of lenses which covers a substantial portion of the radius of the disc. Access of a particular disc track is achieved by deflection of the reading beam, rather than by any physical movement of the head. For read-out, the array focuses light reflected from the disc onto a corresponding array of photodetectors.

Optical disc read/write apparatus

A semiconductor apparatus is provided. The apparatus has a multiple layer heterostructure having first and second material layers having first and second bandgaps, respectively and a semiconductor layer of a third bandgap being fabricated between said material layers, the bottom of the conduction band of said semiconductor layer is below the bottom of the conduction band of said material layers, and the top of the valence band of said semiconductor layer is above the top of the valence band of said material layers, the thickness of said semiconductor layer is chosen sufficient for carrier confinement effects within said semiconductor layer to influence the optical properties of said multiple layer heterostructure, and means for applying an electric field to the multiple layer heterostructure in order to vary an optical absorption coefficient and an index of refraction of the multiple layer heterostructure in response to the electric field. The apparatus is adapted for use as an optical absorption modulator or optical phase modulator, or as an electrically tuned Fabry-Perot cavity or as a polarization modulator, or as a nonlinear or bistable apparatus in which the operating point is varied by application of an electric field.

High speed light modulator using multiple quantum well structures

Tunable laser radiation is obtained by pumping a wedge-shaped ultra-short laser cavity with picosecond excitation pulses. Continuous tuning of the laser is achieved by translating either the wedge-shaped laser cavity or the excitation pulses so that different volumes of the laser material are exposed to the excitation pulses. In one embodiment utilizing picosecond laser excitation pulses the wedge-shaped laser cavity is a slightly wedged film of GaAs coated on both sides with dielectric mirrors.

Tunable semiconductor laser

Broadband laser gain is obtained in semiconductor materials by pumping an ultra-short laser cavity with picosecond excitation pulses. The broadband laser gain is used to provide picosecond laser radiation energy covering a wide spectrum of frequencies.

Semiconductor laser having broadband laser gain

A tunable far infrared generator makes use of a four-photon mixing process that cycles among highly excited atomic states, the lowest of which states is reached from the atomic ground state by a visible or ultraviolet photon, and the remainder of which states are connected by transitions in the infrared.

Generation of tunable far-infrared radiation

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.

Growing community of inventors

Colts Neck, NJ, United States of America

Theodoor Charlouis Damen