The Boeing Company

Trw Limited

Chi-Shain Hong

Luis Figueroa

Eric Y Chan

Jane J Yang

Veeravana S Sundaram

Pamela L Derry

R Jennhwa Fu

A semiconductor laser having increased reliability and enhanced high temperature operation. The device is based upon GaAs/AlGaAs, and comprises a quantum well active layer that is strained by the inclusion of the indium. The rear facet of the device has a high reflectivity coating, and the front facet reflectivity and cavity length are adjusted based upon the required output power. For high output power at high temperature, long cavity lengths and low front facet reflectivities are used. For low current operation and low output power at high temperature, shorter cavities and higher front facet reflectivities are used. The lasers are capable of reliably operating at temperatures up to and in excess of 100.degree. C.

Strained quantum well laser for high temperature operation

The invention relates to the design of multiwavelength LED devices having multiple-lobe optical spectrums and laser diode devices with multiple designated wavelengths wherein the devices are formed by stacking various active layers of selected semiconductor materials whereby each layer is assigned to be active at a different wavelength. The independent layers are active at different wavelengths based on both their material composition and Quantum Well geometry. Independent control of current to each layer is allowed which in effect controls the spectral intensity distribution and the spectral widths. The step of allowing independent control of the current is achieved by considering the probabilities of carrier capturing, recombining carriers at various active layers and minimizing the current through all the barriers and cladding layers and optimizing the current through each active layer by controlling the individual thicknesses. For the LED device, the window and absorption sections within a Transverse Junction Geometry scheme exist to aid in control of the current within the device. For both the LED and laser devices, the active layer region can be varied in thickness in order to tailor the optical intensity of the devices.

Multiwavelength LED and laser diode optical source

A semiconductor laser structure having the same advantages as a channeled substrate planar laser, but without the difficulties of fabrication associated with this structure. The structure includes a substrate, a planar first cladding layer, a planar active layer, and a second cladding layer in which a mesa region is formed. A blocking layer is formed over the second cladding layer and electrical contact is made through the blocking layer in the region of the mesa. The blocking layer functions to confine current flow in the mesa region and to provide index-guiding of light in the mesa region. Because of its simple geometry, the structure can be conveniently formed using a desirable fabrication process, such as metalorganic chemical vapor deposition (MOCVD). In one disclosed embodiment of the invention, the mesa is broadened to include at least one intermediate ledge on each side of a central pedestal. This reduces the abruptness of the change in effective index of refraction encountered by the laser light, and reduces astigmatism in the resultant beam.

Inverted channel substrate planar semiconductor laser

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Bellevue, WA, United States of America

Chi-Shain Hong