Hitachi, Ltd.

Shinko Electric Industries Co., Ltd.

Lumentum Japan, Inc.

Hitachi Global Storage Technologies Japan, Ltd.

Oclaro Japan, Inc.

Renesas Technology Corp.

Hitachi Tobu Semiconductor

Opnext Japan, Inc.

Hitachi Global Storage Technologies

Renesas Eastern Japan Semiconductor, Inc.

Atsushi Nakamura

Tsukasa Nakanishi

Masafumi Mochizuki

Takayuki Matsumoto

Shunya Yamauchi

Tomohiro Okada

Yasutaka Nishida

Hideki Sawaguchi

Takehiko Hamaguchi

Kiyokazu Sato

Hideaki Asakura

Nozomu Yasuhara

Masaaki Futamoto

Yohji Maruyama

Yoshiyuki Hirayama

Yukio Honda

Yoshihiro Nakai

Mikio Suzuki

Kimitoshi Etoh

Shigetaka Hamada

Ryosuke Nakajima

Hayato Takita

Hisashi Takano

Kunihiko Nishi

Toshio Sugano

Aizo Kaneda

Yoshibumi Matsuda

Nobuyuki Inaba

Yoshiaki Kawato

Hiroshi Ide

Masayuki Watanabe

Isao Nunokawa

Futoshi Tomiyama

Yoji Maruyama

Seiichiro Tsukui

Yoshiaki Wakashima

Michio Tanimoto

Suguru Sakaguchi

Michiharu Honda

Kaoru Okamoto

Noriko Sasada

Takeshi Komaru

Takayoshi Fukui

Yoriyoshi Yamaguchi

Tohru Yoshida

Kohji Nagaoka

Kohji Serizawa

Masatoshi Arasawa

Takayuki Tsutsui

Yasuhiro Nakatsuka

Tetsuya Nishida

Masahiro Ichitani

Masahiro Aoki

Kazuhisa Uomi

Tatemi Ido

Makoto Okai

Tomonobu Tsuchiya

Kazushige Yamagishi

Naozumi Morino

Takashi Miwa

Yasushi Sakuma

Takeshi Kitatani

Masayuki Morita

Ryu Washino

Shigeo Yamashita

Shoichi Takahashi

Hiroki Irie

Ikuo Kudo

Takanori Hashizume

Saneaki Tamaki

Haruki Fukai

Yasumi Tsutsumi

Kazuo Kojima

Tsuneo Satoh

Keiji Miyamoto

Hiroshi Fukui

Akira Nakanishi

Moriaki Fuyama

Matahiro Komuro

Kiwamu Tanahashi

Tomoo Yamamoto

Noboru Shimizu

Akira Ishikawa

Yasuyoshi Horikawa

Katsumi Hoshino

Takashi Kawabe

Kouji Nakahara

Yuko Tsuchiya

Masaaki Sano

Kazusuke Yamanaka

Shigenori Hayakawa

Takayuki Nakajima

Takanobu Takayama

Toshihiko Fukamachi

Takashi Shiota

Masato Hagimoto

Mitsuyoshi Imai

Osamu Hoshino

Yuji Sekino

Provided is an electro-absorption modulator that includes a substrate, a mesa structure, a first conductivity type electrode, and a second conductivity type electrode. The first conductivity type electrode includes a mesa-top electrode, a pad electrode, and a lead-out wire electrode. The mesa structure has a light input end, to which light is to be input from outside, and a light output end, which is on a side of the mesa structure that is opposite of the light input end. A connection position between a center position in a short-side direction of the lead-out wire electrode and the mesa-top electrode is closer to the light output end side in a long-side direction of the mesa-top electrode. The connection position is a position that is less than 50% from the light output end side with respect to a length in the long-side direction of the mesa-top electrode.

Electro-absorption modulator

A semiconductor optical amplifier integrated laser includes a semiconductor laser oscillator portion that oscillates laser light having a wavelength included in a gain band and a semiconductor optical amplifier portion that amplifies laser light output from the semiconductor laser oscillator portion. The semiconductor laser oscillator portion and the semiconductor optical amplifier portion have one common p-i-n structure, the common p-i-n structure includes an active layer, a cladding layer provided apart from the active layer, and a common functional layer formed in the cladding layer, and the common functional layer includes a first portion that reflects light having a wavelength within the gain band in the semiconductor laser oscillator portion and a second portion that transmits light having a wavelength within the gain band in the semiconductor optical amplifier portion.

Semiconductor optical amplifier integrated laser

An optical semiconductor device includes a semiconductor substrate with a protrusion that forms a lower end portion of a mesa stripe structure in a stripe shape extending in a first direction; a multi-quantum well layer in a stripe shape extending in the first direction on the protrusion, wherein the multi-quantum well layer forms an intermediate portion of the mesa stripe structure; a semiconductor layer in a stripe shape extending in the first direction on the intermediate portion, wherein the semiconductor layer forms an upper end portion of the mesa stripe structure; and a semi-insulating semiconductor layer in contact with side surfaces of the mesa stripe structure on both sides in a second direction perpendicular to the first direction. The optical semiconductor device may include a first electrode on a surface of the semiconductor substrate and/or a second electrode on the upper end surface of the mesa stripe structure.

Optical semiconductor device and semiconductor light-emitting device

An optical semiconductor device includes a substrate, a semiconductor multilayer which is formed on the substrate, and includes an optical functional layer, an insulating film formed on the semiconductor multilayer, and an electrode formed on a part of the insulating film. The insulating film covers the semiconductor multilayer except for a region in which the semiconductor multilayer and the electrode are electrically connected to each other. At least a part of a region of the insulating film that is overlapped with the electrode is thinner than a region of the insulating film that is not overlapped with the electrode.

Optical semiconductor device

An optical semiconductor device includes a semiconductor substrate; a plurality of mesa stripes, which are arranged side by side on the semiconductor substrate, and each of which includes an active layer and a diffraction grating, the diffraction grating extending up to a back end surface of each of the plurality of mesa stripes; a plurality of electrodes, each of which is electrically connected to an upper surface of a corresponding one of the plurality of mesa stripes, having a pad portion for wire bonding; a plurality of waveguides, each of which is optically connected to the active layer of a corresponding one of the plurality of mesa stripes; and a reflective film provided at back end surfaces of the plurality of mesa stripes, and wherein at least two mesa stripes, of the plurality of mesa stripes, are configured to be driven at the same time.

Optical semiconductor device, optical subassembly, and optical module

To provide an optical semiconductor device having excellent long-term reliability, the optical semiconductor device includes: a substrate; a mesa structure provided on the substrate; a semiconductor burial layer provided in contact with two sides of the mesa structure; and an electrode containing Au, which is provided above the semiconductor burial layer. The mesa structure includes a first conductivity type semiconductor layer, a multiple-quantum well layer, and a second conductivity type semiconductor layer, which are stacked in the stated order from a substrate side. The semiconductor burial layer includes a first semi-insulating InP layer provided in contact with side portions of the mesa structure, a first anti-diffusion layer provided in contact with the first semi-insulating InP layer, and a second semi-insulating InP layer provided on the first anti-diffusion layer. The first anti-diffusion layer has an Au diffusion constant that is smaller than that of the first semi-insulating InP layer.

A semiconductor laser includes: a multi-quantum well layer in a mesa structure; a buried layer comprising a semi-insulating semiconductor, the buried layer being in contact with each of both sides of the mesa structure; a first cladding layer with a first conductivity type, the first cladding layer having a lower refractive index than the multi-quantum well layer; a high refractive index layer configured to not absorb light oscillating in the multi-quantum well layer, the high refractive index layer having a higher refractive index than the first cladding layer; a diffraction grating layer at least partially constituting a diffraction grating capable of diffracting the light oscillating in the multi-quantum well layer, the diffraction grating layer not contacting the high refractive index layer; a substrate with the first conductivity type; and a second cladding layer with a second conductivity type above the multi-quantum well layer.

Semiconductor laser

A transmitter optical subassembly may include an optical modulator for modulating output light from the light source. The optical modulator has a characteristic that a current depending on amount of optical absorption has a positive correlation with an applied voltage thereto. The transistor at the second terminal is connected in series to the optical modulator. A drive voltage applied to the optical modulator and the transistor is divided into a first voltage applied to the optical modulator and a second voltage applied to the transistor. A drive current flowing through the optical modulator and the transistor depends on the control signal input to the first terminal. The first voltage is based on the drive current and is subject to the characteristic of the optical modulator. The second voltage fluctuates in response to the first voltage.

Transmitter optical subassembly and optical module

A electro-absorption optical modulator includes a multiple quantum well composed of a plurality of layers including a plurality of quantum well layers and a plurality of barrier layers that are alternately stacked, the plurality of quantum well layers and the plurality of barrier layers including an acceptor and a donor; a p-type semiconductor layer in contact with an uppermost layer of the plurality of layers; and an n-type semiconductor layer in contact with a lowermost layer of the plurality of layers, the multiple quantum well being 10% or more and 150% or less of the p-type semiconductor layer in a p-type carrier concentration, and in the multiple quantum well, an effective carrier concentration which corresponds to a difference between the p-type carrier concentration and an n-type carrier concentration is &#xb1;10% or less of the p-type carrier concentration of the multiple quantum well.

Electro-absorption optical modulator and manufacturing method thereof

A modulation doped semiconductor laser includes a multiple quantum well composed of a plurality of layers including a plurality of first layers and a plurality of second layers stacked alternately and including an acceptor and a donor; a p-type semiconductor layer in contact with an uppermost layer of the plurality of layers; and an n-type semiconductor layer in contact with a lowermost layer of the plurality of layers, the plurality of first layers including the acceptor so that a p-type carrier concentration is 10% or more and 150% or less of the p-type semiconductor layer, the plurality of second layers containing the acceptor so that the p-type carrier concentration is 10% or more and 150% or less of the p-type semiconductor layer, the plurality of second layers containing the donor, and an effective carrier concentration corresponding to a difference between the p-type carrier concentration and an n-type carrier concentration is 10% or less of the p-type carrier concentration of the plurality of second layers.

Modulation doped semiconductor laser and manufacturing method therefor

Provided is an optical transmission module which can generate PAM4 optical modulation signals without converting a plurality of binary electric signals to a multi-level electric signal. An optical transmission module () comprising: a light source () for emitting continuous waveform (CW) light; optical modulators () arranged in series with a path of the CW light configured to modulate the CW light by switching relatively large absorption and relatively small absorption of the optical modulators in response to a modulation signal applied to the respective optical modulators; and an arithmetic logic circuit () configured to receive a plurality of binary electrical signals, and then to perform logic operation on the plurality of binary electrical signals for generating a new plurality of binary electrical signals, wherein each of the new plurality of binary electrical signals is applied to the respective optical modulators as the modulation signal.

Optical transmission module

An inductor includes a stacked body with a plurality of structural bodies that are stacked. Each of the plurality of structural bodies includes a wiring and an insulation layer formed on the wiring. The wirings of the plurality of structural bodies are connected in series to form a helical coil. The inductor further includes a through hole, which extends through the stacked body in a thickness direction of the stacked body, and a plurality of discrete insulation films, which are spaced apart from each other and cover surfaces of the wires of the plurality of structural bodies exposed from a surface of the stacked body.

Inductor

Provided is an optical transmission module in which noise is further reduced. The optical transmission module includes a first semiconductor layer having a first electrode arranged thereon, an active layer with a stripe shape formed on the first semiconductor layer, and a second semiconductor layer with a stripe shape formed on the active layer. The second semiconductor layer has a second electrode arranged thereon and includes a diffraction grating arranged along an extending direction of the active layer. The active layer includes a first portion having first stripe width, a second portion having a second stripe width smaller than the first stripe width, and a connection portion having a varying stripe width so as to connect the first portion and the second portion to each other. The diffraction grating overlaps with the first portion and does not overlap with the second portion in planar view.

A coil substrate includes a stacked structure in which a plurality of structures are stacked, each of the structures including a first insulating layer and a wiring formed on the first insulating layer, which becomes a part of a spiral-shaped coil; and an insulating film that covers a surface of the stacked structure, the spiral-shaped coil being formed by connecting the wirings of the adjacent structures in series.

Coil substrate, method of manufacturing coil substrate and inductor

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Nagano, Japan

Atsushi Nakamura