Nec Corporation

Kaori Kurihara

Takashi Yoshikawa

Hideo Kosaka

Susumu Asada

Mitsunori Sugimoto

In order to control the polarization direction of laser light emitted by a vertical cavity surface emitting laser (VCSEL), the cross-sectional dimension of the p-DBR is so limited as to permit only a single fundamental transverse mode in a waveguide composed by the p-DBR. Some VCSEL-based devices are developed using arrays of VCSELs in which each VCSEL has a controlled direction of polarization.

VCSELs (vertical-cavity surface emitting lasers) and VCSEL-based devices

In order to control polarization direction of laser light emitted by a vertical cavity surface emitting laser (VCSEL), cross-sectional dimension of the p-DBR is so limited as to permit only a single fundamental transverse mode in a waveguide composed by the p-DBR. Some VCSEL-based devices are developed using arrays of VCSELs in which each VCSEL has a controlled direction of polarization.

The invention provides a vertical-to-surface transmission electro-photonic semiconductor device with a mesa structure of light reflective multiple layers in which the device includes a high resistive region for a carrier confinement. The high resistive region is formed by an ion-implantation of proton in a downward oblique direction during a rotation of a semiconductor substrate with use of a photo-resist mask whose horizontal width is larger than that of the mesa structure. The high resistive region defines a light emitting area of an active layer, an inverse circular truncated cone like definition of a top cladding region and a circular truncated cone like definition of a bottom cladding region. The oblique angle ion-implantation permits the top cladding region to be free from any exposure of the ion-implantation thereby an electrical resistance of the device is reduced.

Vertical-to-surface transmission electro-photonic device with ion

A semiconductor multilayer reflector (Distributed Bragg Reflector) includes a plurality of first quarter-wavelength layers each having a high refractive index, a plurality of second quarter-wavelength layers each having a low refractive index, and high concentration impurity doping regions. The first and second layers are piled up alternately, and each of the doping regions is formed at a heterointerface between the first and second layer. In this structure, the width and the height of the potential barrier at the heterointerface becomes small, so that tunnel current flowing through the multilayer reflector is increased.

Semiconductor multilayer reflector and light emitting device with the

An optical device has a multi-layer reflecting structure provided in association with an active layer for allowing light to oscillate, and the multi-layer reflecting structure is implemented by a plurality of units each having a high refractive film, a low refractive film and a layer for improving conductivity of the multi-layer reflecting structure, wherein the layer is implemented by a heavily doped impurity region with an impurity profile tracing plots of a delta function or by a quasi-graded super-lattice film microscopically graded in composition between the high and low refractive films.

Growing community of inventors

Tokyo, Japan

Kaori Kurihara