General Electric Company

David Sarnoff Research Center, Inc.

Gary A Evans

Nils W Carlson

Jacob M Hammer

Charlie J Kaiser

Michael Ettenberg

Jay B Kirk

An optical amplifier comprising a substrate of a semiconductor material having a pair of opposed surfaces and a body of semiconductor material on one of the surfaces. The body includes a pair of clad layers of opposite conductivity types having an intermediate quantum wall region therebetween. The clad layers are of a semiconductor material which form a heterojunction with the material of the quantum well region. The clad layers and quantum well region forms a waveguide which extends along the body. A gain section is in the body along the waveguide. The gain section includes a capping layer over the outermost clad layer, a contact on the capping layer and a contact on the other surface of the substrate to allow a voltage to be applied across the gain section. The gain section is adapted to generate light in the active region when a voltage is applied thereacross. A light input section having a grating extending across the body is at one end of the gain section. The light input section is adapted to direct light into the body and along the waveguide. A light output section having a grating extending across the body is at the other end of the gain section. The light output section is adapted to direct the amplified light from the gain section out of the body. The periods of the gratings are such that no self-oscillation of the light in the waveguide occurs.

Optical amplifier

A diode laser array comprises a substrate of a semiconductor material having first and second opposed surfaces. On the first surface is a plurality of spaced gain sections and a separate distributed Bragg reflector passive waveguide at each end of each gain section and optically connecting the gain sections. Each gain section includes a cavity therein wherein charge carriers are generated and recombine to generate light which is confined in the cavity. Also, the cavity, which is preferably a quantum well cavity, provides both a high differential gain and potentially large depth of loss modulation. Each waveguide has a wavelength which is preferably formed by an extension of the cavity of the gain sections and a grating. The grating has a period which provides a selective feedback of light into the gain sections to supporting lasing, which allows some of the light to be emitted from the waveguide normal to the surface of the substrate and which allows optical coupling of the gain sections. Also, the grating period provides an operating wavelength which is on the short wavelength side of the gain period of the gain sections required for laser oscillation. An RF pulse is applied so as to maximize the magnitude of the loss modulation and the differential gain in the gain sections. The array is operated by applying a DC bias to all the gain sections at a level just below the threshold of the gain sections to only one of the gain sections which raises the bias in all of the gain sections to a level that causes all of the gain sections to oscillate. Thus, a small bias can turn the array on and off.

Diode laser array

A superluminescent diode has one end coupled to a DBR having a grating and the other end has a reflective coating. A broadlight spectrum is emitted for reduced speckle interference and phase noise when used in applications such as a gyroscope. The diode can be of the 'P side down' type for good heat dissipation during continuous wave operation. Two gratings can be used in order to reduce beam divergence.

Grating-coupled surface-emitting superluminescent device

A first array of laser diode devices are optically coupled by a diffraction grating comprising a plurality of spaced diffraction nodules in a grid array optically coupled to the devices. The light emitted from a device of the first array can pass through the grid array to a second device, reflect back to the emitting device in a Distributed Bragg Reflector (DBR) mode and deflect orthogonal to the emitted light optical axis to a third device in a Distributed Bragg Deflector (DBD) mode. The light from the second and third devices can be coupled to other laser diode devices by still further diffraction nodule arrays to produce phased-locked beams; beam steering of portions of the light and other effects.

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West Windsor Township, NJ, United States of America

Gary A Evans