Mitsubishi Denki Kabushiki Kaisha

Mitsubishi Electric Corporation

Kimio Shigihara

Kazushige Kawasaki

Toshitaka Aoyagi

Yutaka Nagai

Kenichi Ono

Yoshihiko Hanamaki

Kenji Ikeda

Kimitaka Shibata

Satoshi Nishikawa

Takeshi Fujita

Shinji Abe

Kiyohide Sakai

Yutaka Mihashi

Yasuaki Yoshida

Akihito Ohno

Daisuke Morita

Akira Takemoto

Etsuji Omura

Tatsuo Hatta

Tomohiro Kyoto

Hiromasu Matsuoka

Keisuke Furuta

Ryoichi Hirano

Akihito Ono

Naoyuki Shimada

Yuuhiko Hamada

Takuto Maruyama

A semiconductor laser device is provided with a semiconductor layer including an active layer and a plurality of cladding layers sandwiching the active layer. The active layer includes a stripe-shaped active region, a pair of first refractive index regions and a pair of second refractive index regions sandwiching the active layer and the pair of first refractive index regions. When λ is the laser oscillation wavelength, nis the effective refractive index of the active region, nis the effective refractive index of the first refractive index regions, nis the effective refractive index of the second refractive index regions, w is the width of the active region, and m is a positive integer, the semiconductor laser device satisfies n>n>n, and the conditions of equations (5), (8) and (9).

Semiconductor laser device

A semiconductor laser machine includes a semiconductor laser element including a first end face that emits a laser beam and a second end face that is opposite the first end face; a heat sink; and a sub-mount securing the semiconductor laser element to the heat sink. The sub-mount includes a substrate that serves as a thermal stress reliever, a solder layer joined to the semiconductor laser element, and a junction layer formed between the substrate and the solder layer. Compared with the semiconductor laser element, the substrate is extended in a rearward direction that is from the first end face toward the second end face. As for the solder layer and the junction layer, a portion of at least the solder layer is removed behind the second end face.

Semiconductor laser machine

A broad area semiconductor laser device includes a waveguide region and a filter region. The waveguide region includes an active region into which current is injected, and a cladding region that sandwiches the active region. The active region either protrudes or is recessed with respect to the filter region, so as to promote the divergence of higher order modes in the filter region.

Broad area semiconductor laser device

An active layer is provided on a side closer to the second conductivity type cladding layer than a center of the light guide layer in the light guide layer. A first conductivity type low-refractive-index layer is formed between the first conductivity type cladding layer and the light guide layer and has a refractive index which is lower than a refractive index of the first conductivity type cladding layer. A layer thickness d of the light guide layer is a value at which a high-order mode equal to or higher than a first-order mode is permissible in a crystal growing direction by satisfying The active layer is disposed at a position where a light confinement of the active layer becomes smaller compared to a case in which the active layer is disposed at a center of the light guide layer while there is not the first conductivity type low-refractive-index layer.

A method of manufacturing a semiconductor laser device includes the steps of: preparing the semiconductor laser bar body including a top surface, an undersurface, two mutually opposing facets, and two mutually opposing side faces, performing a coating step to form a coating film on the facet, and performing a division step after the coating step. The division step performs scribing on and divides the semiconductor laser bar body. A groove is formed on the facet by denting the facet, or is formed in the coating film by exposing a part of the facet, and the groove extends from the top surface to the undersurface. A width of the groove is 20 &#x3bc;m. Scribing is performed on the top surface or the undersurface so that a scribed track or an extended line of the scribed track meets the groove.

Semiconductor laser device and manufacturing method thereof

A semiconductor laser device includes an n-type semiconductor substrate, an n-type cladding layer laminated on the semiconductor substrate, an n-side light guiding layer laminated on the n-type cladding layer, an active layer laminated on the n-side light guiding layer, a p-side light guiding layer laminated on the active layer, and a p-type cladding layer laminated on the p-side light guiding layer. The sum of the thicknesses of the n-side and p-side light guiding layers is such that the first and higher order modes of oscillation can occur in the crystal growth direction. A low refractive index layer having a lower refractive index than the n-type cladding layer is located between the n-side light guiding layer and the n-type cladding layer, and the active layer is displaced from the lateral center plane of the light guiding layer structure toward the p-type cladding layer.

A semiconductor laser device includes a first conductivity type semiconductor substrate, a first conductivity type cladding layer, a first light guide layer, an active layer, a second light guide layer, and a second conductivity type cladding layer laminated on the semiconductor substrate in that order. The semiconductor laser device supports at least one of a first-order and higher-order mode of oscillation in the semiconductor laser in crystal growth direction of the active layer. The first light guide layer is thicker than the second light guide layer. A first conductivity type low refractive index layer having a lower refractive index than refractive index of the first conductivity type cladding layer, is disposed between the first conductivity type cladding layer and the first light guide layer. The refractive index of the second light guide layer is higher than the refractive index of the first light guide layer.

A semiconductor laser includes a ridge section on top of a semiconductor laminated section. The ridge section is a stripe-shaped projection or ridge and serves as a constriction structure for constricting current and light. A pair of terrace sections is located on top of the semiconductor laminated structure. The terrace sections are raised island portions sandwiching and spaced from the ridge section. An active region is located below the ridge section as viewed in plan. High refractive index regions are located on both sides of the active region and below the terrace sections, respectively. Cladding regions are located between the active region and the high refractive index regions. The high refractive index regions have a higher refractive index than the cladding regions.

A semiconductor laser includes: a DBR (Distributed Bragg Reflector) region having a diffraction grating; a FP (Fabry-Perot) region having no diffraction grating; and an optical waveguide section placed between the DBR region and an outputting end surface. A length of the optical waveguide section is longer than a length of the DBR region in a resonator length direction.

Semiconductor laser

An 830 nm broad area semiconductor laser having a distributed Bragg reflector (DBR) structure. The semiconductor laser supports multiple horizontal transverse modes of oscillation extending within a plane perpendicular to a crystal growth direction of the laser, in a direction perpendicular to the length of the resonator of the laser. The resonator includes a diffraction grating in the vicinity of the emitting facet of the laser. The width of the diffraction grating in a plane perpendicular to the growth direction and perpendicular to the length of the resonator is different at first and second locations along the length of the resonator. The width of the diffraction grating along a direction which is perpendicular to the length of the resonator increases with increasing distance from the front facet of the semiconductor laser.

A semiconductor laser device can suppress electrode-to-electrode resonance of laser light emitted from an active layer, increasing electrical conversion efficiency. The semiconductor laser device has a substrate and an active layer. The energy of the laser light emitted from the active layer is smaller than the band gap energy of the substrate, and the carrier concentration of the substrate is at least 2.2&#xd7;10cm.

A semiconductor laser device includes: an n-type cladding layer, a p-type cladding layer, an active layer located between the n-type cladding layer and the p-type cladding layer, an n-side guiding layer located on the same side of the active layer as the n-type cladding layer, and a p-side guiding layer located on the same side of the active layer as the p-type cladding layer. The n-side guiding layer, the active layer, and the p-side guiding layer are undoped or substantially undoped. The sum of the thicknesses of the n-side guiding layer, the active layer, and the p-side guiding layer is not less than 0.5 times the lasing wavelength of the semiconductor laser device and is not more than 2 &#x3bc;m. The p-side guiding layer is thinner and has a lower refractive index than the n-side guiding layer.

A semiconductor laser device includes: an n-type cladding layer; a p-type cladding layer; and an optical waveguide portion disposed between the n-type and p-type cladding layers and including spaced-apart active layers. The optical waveguide portion permits lasing in a crystal growth direction of the active layers in at least three modes, including the fundamental mode and two higher order modes. The number of active layers is equal to or greater than the number of extreme points of the electric field of a particular one of the higher order modes. At least one of the active layers is disposed near each extreme point of the electric field of the particular higher order mode, within the optical waveguide portion.

A coating film is provided on an end surface of a semiconductor photonic element including an active layer through which light propagates. The coating film has a two-layer structure including a first layer film and a second layer film arranged in a stacked relation. The thicknesses of the first and second layer films are determined so that the value of the amplitude reflectivity of the coating film is equal to an imaginary number.

Semiconductor photonic device

A semiconductor laser apparatus can improve electric conversion efficiency to a satisfactory extent. The apparatus includes an n-type cladding layer, an n-type cladding layer side guide layer, an active layer, a p-type cladding layer side guide layer, and a p-type cladding layer, wherein electrons and holes are injected into the active layer, transverse to the active layer, through the n-type cladding layer side guide layer and the p-type cladding layer side guide layer. The p-type cladding layer side guide layer is thinner than the n-type cladding layer side guide layer to position the active layer closer to the p-type cladding layer, and, at the same time, the refractive index of the p-type cladding layer side guide layer is higher than the refractive index of the n-type cladding layer side guide layer.

Growing community of inventors

Tokyo, Japan

Kimio Shigihara