Sumitomo Electric Industries, Limited

Masaki Yanagisawa

Hiroshi Yano

Hirohiko Kobayashi

Yoshihiro Yoneda

Yukihiro Tsuji

Kenji Koyama

Kenji Hiratsuka

Seiji Yaegashi

Kenji Kotani

Takeshi Kawasaki

Hiroyuki Yoshinaga

Yuji Koyama

A surface emitting laser includes a substrate, a mesa of semiconductor layers including a lower reflector layer, an active layer, an upper reflector layer, and an upper contact layer that are successively laminated on the substrate, and an electrode provided on the upper contact layer. The upper contact layer includes GaAs. The electrode includes an alloy layer including Pt, in contact with the upper contact layer.

Surface emitting laser

A surface emitting semiconductor laser includes a post disposed on a substrate, the post including an active layer and a distributed Bragg reflector; a first insulating layer disposed on side and top surfaces of the post and on the substrate, the first insulating layer having an opening on the top surface of the post; an electrode disposed in the opening of the first insulating layer; an electric conductor including a pad electrode on the first insulating layer, the electric conductor extending on the first insulating layer to the electrode; and a second insulating layer disposed on the first insulating layer, the electrode, and the electric conductor so as to cover the electrode in the opening of the first insulating layer, the second insulating layer having an opening on the pad electrode, the opening of the second insulating layer having an edge on a top surface of the pad electrode.

Surface emitting semiconductor laser

A method fix forming a diffraction grating includes the steps of preparing a mold including pattern portions each having a pattern corresponding to a pattern for the diffraction grating; forming a first semiconductor layer on a substrate; forming a resin layer on the first semiconductor layer; pressing the pattern portions of the mold against the resin layer; forming the pattern for the diffraction grating in the resin layer by curing the resin layer; and forming the diffraction grating in the first semiconductor layer by etching the first semiconductor layer using the patterned resin layer. The mold includes a first base and a plurality of second bases disposed on the first base. The first base is made of a flexible material. Each second base is made of a rigid material. The second bases each include one pattern portion and are spaced apart from each other with a predetermined distance.

Mold for nano-imprinting, method for forming diffraction grating, and method for producing optical device including diffraction grating

A semiconductor optical integrated device includes a substrate having a main surface with a first and second regions arranged along a waveguiding direction; a gain region including a first cladding layer, an active layer, and a second cladding layer arranged on the first region of the main surface; and a wavelength control region including a third cladding layer, an optical waveguide layer, and a fourth cladding layer arranged on the second region of the main surface and including a heater arranged along the optical waveguide layer. The substrate includes a through hole extending from a back surface of the substrate in the thickness direction and reaching the first region. A metal member is arranged in the through hole. The metal member extends from the back surface of the substrate in the thickness direction and is in contact with the first cladding layer.

Semiconductor optical integrated device

A method of forming a sampled grating includes the steps of preparing a substrate; preparing a nano-imprinting mold including a pattern surface on which projections and recesses are periodically formed; preparing a mask including a light obstructing portion and a light transmitting portion that are alternately provided; forming a photoresist layer and a resin portion in that order on the substrate; forming a patterned resin portion having projections and recesses by pressing the pattern surface of the mold into contact with the resin portion and hardening the resin portion while maintaining the contact; exposing a portion of the photoresist layer by irradiating the photoresist layer with exposing light through the mask and the patterned resin portion; forming a patterned photoresist layer by developing the photoresist layer; and etching the substrate using the patterned photoresist layer.

Method of forming a sampled grating and method of producing a laser diode

A nano-imprint mold includes a mold base; mold body having a first surface and a second surface opposite the first surface; and an elastic body disposed between a surface of the mold base and the first surface of the mold body, the elastic body being composed of resin. The second surface of the mold body is provided with a nano-imprint pattern. In addition, the elastic body has a bulk modulus lower than a bulk modulus of the mold body.

Nano-imprint mold

A process using the nanoimprint technique to form the diffraction grating for the DFB-LD is disclosed. The process includes (a) coating a resist for the EB exposure on a dummy substrate, (b) irradiating the resist as varying the acceleration voltage, (c) forming a resist pattern by developing the irradiated resist, (d) coating the SOG film on the patterned resist, (e) attaching the silica substrate on the cured SOG film, and (f) removing the dummy substrate with the resist from the SOG film and the silica substrate. Using the mold thus formed, the diffraction grating for the DFB-LD is formed by the nanoimprint technique.

Process to form a mold of nanoimprint technique for making diffraction grating for DFB-LD

A nano-imprint mold includes a mold body having a first surface provided with a pattern having projections and recesses, a second surface opposite the first surface and a side surface between the first surface and the second surface; and a mold base having a surface for fixing the mold body thereto. In addition, the second surface of the mold body is fixed to a part of the surface of the mold base, the second surface of the mold body being disposed away from at least a part of an edge of the surface of the mold base. Furthermore, the mold body has a shape such that a width thereof in a direction orthogonal to a direction extending from the first surface toward the second surface decreases from the first surface toward the second surface.

Method for manufacturing nano-imprint mold, method for forming resin pattern by nano-imprint technique, and nano-imprint mold

A method for producing a semiconductor optical integrated device includes the steps of forming a substrate product including first and second stacked semiconductor layer portions; forming a first mask on the first and second stacked semiconductor layer portions, the first mask including a stripe-shaped first pattern region and a second pattern region, the second pattern region including a first end edge; forming a stripe-shaped mesa structure; removing the second pattern region of the first mask; forming a second mask on the second stacked semiconductor layer portion; and selectively growing a buried semiconductor layer with the first and second masks. The second mask includes a second end edge separated from the first end edge of the first mask, the second end edge being located on the side of the second stacked semiconductor layer portion in the predetermined direction with respect to the first end edge of the first mask.

Method for producing semiconductor optical integrated device

A method for manufacturing a semiconductor laser includes the steps of preparing a mold with a pattern surface having recesses, forming a stacked semiconductor layer including a grating layer, forming a resin part on the grating layer, forming a resin pattern portion on the resin part, forming a diffraction grating by etching the grating layer using the resin part as a mask, and forming a mesa-structure on the stacked semiconductor layer. Each of the recesses includes two end portions and a middle portion between the two end portions. A depth of at least one of the two end portions from the pattern surface is greater than that of the middle portion. The step of forming the mesa-structure includes the step of etching the stacked semiconductor layer so as to remove end portions of the diffraction grating in a direction orthogonal to a periodic direction thereof.

Method for manufacturing semiconductor laser

A method of making a semiconductor optical integrated device includes the steps of forming, on a substrate, a plurality of semiconductor integrated devices including a first optical semiconductor element having a first bonding pad and a second optical semiconductor element; forming a plurality of bar-shaped semiconductor optical integrated device arrays by cutting the substrate, each of the semiconductor optical integrated device arrays including two or more semiconductor optical integrated devices; alternately arranging the plurality of semiconductor optical integrated device arrays and a plurality of spacers in a thickness direction of the substrate so as to be fixed in place; and forming a coating film on a facet of the semiconductor optical integrated device array. Furthermore, the spacer has a movable portion facing the first bonding pad, the movable portion protruding toward the first bonding pad and being displaceable in a protruding direction.

Method of making semiconductor optical integrated device by alternately arranging spacers with integrated device arrays

The present invention is to provide a method for manufacturing a planar optical waveguide and a micro-lens using a transcribed resin formed by the optical nano-imprint technique. The method includes a step for forming a resin contained with ultraviolet curable materials on the substrate. The mold is pressed against the resin. This step forms a patterned resin that reflects the pattern formed in the mold. After hardening the resin by irradiating the ultraviolet rays, the resin is cooled down as the mold is pressed against the resin from the temperature T, where the mold is pressed, to Tbelow T. After cooling down the temperature of the resin, the mold is detached to complete the resin with the pattern transcribed from the mold.

Method for transcribing patterns on resin body, method for manufacturing planar waveguide, and method for manufacturing micro-lens

A method of forming a diffraction grating according to the present invention includes a step of preparing a mold having projections and recesses for forming a diffraction grating, a step of bringing the projections and recesses of the mold into contact with a resin layer in a chamber at a first pressure less than atmospheric pressure, a step of setting a pressure in the chamber to a second pressure more than the first pressure while maintaining the contact, and a step of hardening the resin layer while maintaining the contact between the resin layer and the projections and recesses so as to form a pattern for the diffraction grating on the hardened resin layer. The recesses in the projections and recesses of the mold form a closed pattern in the plane of the mold including the projections and recesses.

Method of forming diffraction grating and method of fabricating distributed feedback laser diode

A method for forming a grating with an adjustable pitch and a method for forming a DFB-LD with an optical grating whose pitch is adjustable during the process are disclosed. The method of the invention; first prepares a mold with a pattern to form the grating; second, pushes the mold against the resin as deforming the mold; and third, hardens the mold. The resin with a periodic pattern whose pitch is adjustable during the process is available.

Method to form an optical grating and to form a distributed feedback laser diode with the optical grating

This invention provides a double hetero-junction bipolar transistor (DHBT) in which a probability of the impact ionization at the interface between the base and the collector is reduced, thereby enhancing the break down voltage. In the present DHBT, a plurality of transition layers is inserted between the base layer and the collector layer. Each transition layers has an energy band gap gradually increasing from the base to the collector, and comprises a doped layer close to the base and an un-doped layer. Transition layers thus configured may bring both characteristics of the high break down voltage by the reduction of the average doping concentration and the capability of the high-speed operation by the reduction of the junction capacitance.

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Yokohama, Japan

Masaki Yanagisawa