The Furukawa Electric Co., Ltd.

Satoshi Irino

Junji Yoshida

Taketsugu Sawamura

Hirokazu Itoh

Yuichiro Irie

Naoki Tsukiji

Masaki Funabashi

Nobumasa Tanaka

Hideaki Hasegawa

Akihiko Kasukawa

Noriyuki Yokouchi

Hidehiro Taniguchi

Tsuyoshi Saito

Ryuichiro Minato

Harunobu Ikeda

Masako Kobayakawa

An optical semiconductor device outputting a predetermined wavelength of laser light includes a quantum well active layer positioned between a p-type cladding layer and an n-type cladding layer in thickness direction. The optical semiconductor device includes a separate confinement heterostructure layer positioned between the quantum well active layer and the n-type cladding layer. The optical semiconductor device further includes an electric-field-distribution-control layer positioned between the separate confinement heterostructure layer and the n-type cladding layer and configured by at least two semiconductor layers having band gap energy greater than band gap energy of a barrier layer constituting the quantum well active layer. The optical semiconductor device is applied to a ridge-stripe type laser.

Wavelength-variable laser

An optical semiconductor device outputting a predetermined wavelength of laser light includes a quantum well active layer positioned between a p-type cladding layer and an n-type cladding layer in thickness direction. The optical semiconductor device includes a separate confinement heterostructure layer positioned between the quantum well active layer and the n-type cladding layer. The optical semiconductor device further includes an electric-field-distribution-control layer positioned between the separate confinement heterostructure layer and the n-type cladding layer and configured by at least two semiconductor layers having band gap energy greater than band gap energy of a barrier layer constituting the quantum well active layer. The quantum well active layer is doped with 0.3 to 1&#xd7;10/cmof n-type impurity.

A distributed feedback (DFB) laser outputting a predetermined wavelength of laser light includes a quantum well active layer positioned between a p-type cladding layer and an n-type cladding layer in thickness direction. The DFB laser includes a separate confinement heterostructure layer positioned between the quantum well active layer and then-type cladding layer. The DFB laser includes an electric-field-distribution-control layer positioned between the separate confinement heterostructure layer and then-type cladding layer and configured by at least two semiconductor layers having band gap energy greater than band gap energy of a barrier layer constituting the quantum well active layer. The DFB laser has a function to select a specific wavelength by returning a specific wavelength in the wavelength-variable laser.

A wavelength-variable laser outputting a predetermined wavelength of laser light includes: a quantum well active layer positioned between a p-type cladding layer and an n-type cladding layer in thickness direction; a separate confinement heterostructure layer positioned between the quantum well active layer and the n-type cladding layer; and an electric-field-distribution-control layer positioned between the separate confinement heterostructure layer and the n-type cladding layer and configured by at least two semiconductor layers having band gap energy greater than band gap energy of a barrier layer constituting the quantum well active layer.

An optical semiconductor device outputting a predetermined wavelength of laser light includes: a quantum well active layer positioned between a p-type cladding layer and an n-type cladding layer in thickness direction; a separate confinement heterostructure layer positioned between the quantum well active layer and the n-type cladding layer; and an electric-field-distribution-control layer positioned between the separate confinement heterostructure layer and the n-type cladding layer and configured by at least two semiconductor layers having band gap energy greater than band gap energy of a barrier layer constituting the quantum well active layer.

Optical semiconductor device, semiconductor laser module, and optical fiber amplifier

A method of designing a semiconductor laser device includes: controlling a distance between the output-side reflection unit and the second reflection unit and an effective optical feedback &#x3ba; to the semiconductor laser element, the effective optical feedback &#x3ba; defined by a below-presented formula (1) including a circulating time &#x3c4; of the light in the semiconductor laser element, a reflectivity Rof the output-side reflection unit, and a reflectivity Rof the second reflection unit; selecting a semiconductor laser device in which an LFF period is equal to or smaller than 20 ns as a semiconductor laser device in which high speed switching occurs between an FBG mode and an FP mode; and using the selected semiconductor laser device as an semiconductor laser device oscillating in a coherent collapse mode.&#x3ba;=(1/&#x3c4;)&#xd7;(1&#x2212;)&#xd7;()&#x2003;&#x2003;(1)

Method of designing semiconductor laser device, method of designing raman amplifier, methods of manufacturing semiconductor laser device, semiconductor laser device, raman amplifier, and optical communication system

A semiconductor device of the invention is formed so that n-type InP current blocking layers enter the inside of p-type InP cladding layers, i.e., the n-type current blocking layers ride over the upper part of the p-type InP cladding layers, so that a distance between the n-type InP current block layers composing a current blocking region is narrower than a width of the p-type cladding layers contacting with the n-type InP current blocking layers. Thereby, the semiconductor device whose leak current in the current blocking region may be reduced which permits high-output and high-temperature operations may be readily fabricated.

Optical semiconductor device and pumping light source for optical fiber amplifier

A semiconductor laser device with an active layer having a multi-quantum well structure including more than one well layer and more than one barrier layer and having a cavity length of more than 800 &#x3bc;m is disclosed, wherein the active layer includes a doped region which includes at least one well layer and at least one barrier layer adjacent to the well layer. The entire active region, comprising all of the well and active layers may be doped. Adjacent to the active layer are upper and lower optical confinement layers falls having a thickness within a range of from about 20 to about 50 nm. A optical fiber amplifier incorporating the semiconductor laser is also disclosed, including the semiconductor laser device sealed within a package disposed over a cooler, and wherein a light incidence facet of an optical fiber is optically coupled to the optical output power facet of the semiconductor laser device.

Semiconductor laser device and optical fiber amplifier using the same

A semiconductor laser device which has a diffraction grating partially provided in the vicinity of an active layer formed between a radiation-side reflection film provided on a radiation-side end surface of a laser beam and a reflection film provided on a reflection-side end surface of the laser beam, and which outputs a laser beam having a desired oscillation longitudinal mode based on a wavelength selection characteristic of at least the diffraction grating. The diffraction grating is formed in isolation with an isolation distance of Ls=15 &#x3bc;m from the radiation-side reflection film.

Semiconductor laser device, semiconductor laser module, and Raman amplifier using the device or module

When manufacturing semiconductor elements, a group of semiconductor elements having a diffraction grating formed partly on the side of the facet from which laser light is emitted is formed collectively on a semiconductor wafer by using semiconductor process technologies. The semiconductor laser elements are arranged such that the light emitting facets are opposite to each other to thereby form each diffraction grating of the semiconductor laser elements arranged opposite to each other as one diffraction grating, cleaving this diffraction grating at respective cleavage planes to cut out laser bars, followed by the cleavage of cleavage planes to cut out semiconductor laser elements.

Method of manufacturing semiconductor element, and semiconductor element manufactured with this method

A diffraction grating is provided in the vicinity of a GRIN-SCH-MQW active layer formed between a radiation side reflection coating provided on a radiation end face of a laser beam and a reflection coating provided on a reflection end face of the laser beam, and on the radiation side reflection coating side. An n-InP layer which covers the upper part of the diffraction grating is also provided, so that the current from the p-side electrode is prevented from being injected to the vicinity of the diffraction grating by the n-InP layer. An n-InPGaAsP diffusion prevention layer forms a non-current injection area so as to suppress alloying with the p-side electrode.

Semiconductor laser device, semiconductor laser module, Raman amplifier using the device or module, and method for forming a suitable current blocking layer

Growing community of inventors

Tokyo, Japan

Satoshi Irino