Mitsubishi Denki Kabushiki Kaisha

Nippon Paper Industries Co., Ltd.

Mitsubishi Electric Corporation

Yasuaki Yoshida

Harumi Nishiguchi

Takuya Takahashi

Tetsuya Yagi

Hitoshi Tada

Takeo Suzuki

Tsutomu Yamaguchi

Takehiro Nishida

Yusuke Sugiyama

Takashi Ino

Takeshi Fujita

Kimio Shigihara

Kazushige Kawasaki

Kiyohide Sakai

Yutaka Mihashi

Hirotaka Kizuki

Motoharu Miyashita

Shoichi Karakida

Akira Takemoto

Go Sakaino

Tatsuo Hatta

Yoshihiro Hisa

Yuji Ohkura

Yasutomo Kajikawa

Yasuo Nakajima

Morio Matsuzaki

Masao Aiga

Norimasa Kumada

Narihiro Ilo

Yuuhiko Hamada

Narihiro Iio

Shin'ichi Yamamura

Hirosuke Tsunoda

Syunji Sekiguchi

The present invention provides a hard coat film that is provided with a hard coat layer via an easy-bonding layer on at least one surface of a cycloolefin film, has excellent temporal adhesiveness under normal condition and under moisture and heat resistant condition, and has no crack occurrence under the heat resistant condition. A hard coat filmof the present invention is provided with a hard coat layervia an easy-bonding layeron at least one surface of a cycloolefin film. The easy-bonding layerincludes a mixture of a polyolefin based resin and a styrene-acryl based resin, and a blending ratio thereof is in the range of, for example, from 95/5 to 40/60. Further, the hard coat layerincludes an ionizing radiation curable resin having a weight-average molecular weight of 700 or larger and 3600 or smaller.

Hard coat film

The present invention provides a hard coat film having excellent adhesion to a hard coat layer when a cycloolefin polymer film is used as a base material. The hard coat film of the present invention comprises a hard coat layer containing an ionizing radiation curable resin laminated on at least one surface of a cycloolefin polymer base film through a primer layer. This primer layer contains a modified polyolefin resin in which a polyolefin resin is graft-modified with an α,β-unsaturated carboxylic acid or a derivative thereof, and a (meth)acrylic acid ester. In this modified polyolefin resin, the graft weight of the α,β-unsaturated carboxylic acid or derivative thereof is 0.4 to 7 wt. % when the amount of the modified polyolefin resin is taken as 100 wt. %.

Hard coat film and method for producing same

A hard coat film having excellent adhesion (particularly adhesion over time) to a hard coat layer when a cycloolefin polymer film is used as a base material. The hard coat film comprises a hard coat layer containing an ionizing radiation curable resin laminated on at least one surface of a cycloolefin polymer base film via a primer layer. The primer layer has an arithmetic average surface roughness (Ra) in the range of 0.5 nm to 15.0 nm, and a surface of the primer layer has a static friction coefficient in the range of 0.6 to 2.0.

A semiconductor laser is provided which emits laser light in which the intensity center of the far-field pattern in the horizontal direction does not vary with variation of the optical output and in which the shape of the far-field pattern in the horizontal direction is stable. The width of trenches is determined so that the magnitude (E) of the electric field at the center of a ridge and the magnitude (E) of the electric field at the edges of the trenches provide a ratio E/Ethat is larger than 0.0001 and smaller than 0.01. In a semiconductor laser with a double-channel ridge structure, layers having a larger equivalent refractive index than the trenches exist outside the trenches. Accordingly, the semiconductor absorbs the light distributed outside the trenches and it is possible to obtain laser light in which the intensity center of the far-field pattern in the horizontal direction does not vary with variation of the optical output and in which the shape of the far-field pattern in the horizontal direction is stable.

Semiconductor laser

A semiconductor laser is provided which emits laser light in which the intensity center of the far-field pattern in the horizontal direction does not vary with variation of the optical output and in which the shape of the far-field pattern in the horizontal direction is stable. The width of trenches is determined so that the magnitude (E) of the electric field at the center of a ridge and the magnitude (E) of the electric field at the edges of the trenches provide. a ratio E/Ethat is larger than 0.0001 and smaller than 0.01. In a semiconductor laser with a double-channel ridge structure, layers having a larger equivalent refractive index than the trenches exist outside the trenches. Accordingly, the semiconductor absorbs the light distributed outside the trenches and it is possible to obtain laser light in which the intensity center of the far-field pattern in the horizontal direction does not vary with variation of the optical output and in which the shape of the far-field pattern in the horizontal direction is stable.

A semiconductor laser device includes a cavity extending in a propagation direction of a laser beam (X-direction). A front facet is on one end of the cavity through which the laser beam is emitted. A rear facet is on the other end of the cavity. Further, an adhesive layer and a coating film are on the front facet, and an adhesive layer and a coating film are on the rear facet. The adhesive layers preferably have a thickness of 10 nm or less and preferably include an anodic oxide film of one of Al, Ti, Nb, Zr, Ta, Si, and Hf.

Semiconductor laser device

A semiconductor laser device includes a cavity extending in a propagation direction of a laser beam (X-direction). A front facet is on one end of the cavity through which the laser beam is emitted. A rear facet is on the other end of the cavity. An anodic oxide film is provided on at least one of the front facet and the rear facet, and the anodic oxide film preferably has a thickness of &#x3bb;/4n or an odd integer multiple thereof, where &#x3bb; is the wavelength of the laser beam and n is the refractive index of the anodic oxide film.

A semiconductor laser device has an n-GaAs substrate. On the n-GaAs substrate, by turns, are an n-AlGaInP cladding layer, an AlGaInP/GaInP MQW active layer, a p-AlGaInP first cladding layer, a single layer p-AlGaAs etching stopping layer, a p-AlGaInP second cladding layer with a stripe protrusion, and a p-GaAs contact layer. The portion, other than the stripe-form protrusion, of the p-AlGaInP second cladding layer is covered with an insulating film. The refractive index of the p-AlGaAs-ESL is nearly equal to the refractive index of each of the lower, first upper, and second upper cladding layers.

A semiconductor laser device includes a lower cladding layer of n-(Al0.66Ga0.34)0.5In0.5P, an active layer having a window structure which has a disordered MQW structure, a first upper cladding layer of p-(Al0.7Ga0.3)0.5In0.5P, and a second upper cladding layer of (Al0.66Ga0.34)0.5In0.5P sequentially disposed on an n-GaAs substrate. The refractive index of the first upper cladding layer is smaller than that of the lower cladding layer, and refractive index of the second upper cladding layer is larger than that of the first upper cladding layer and identical to that of the lower cladding layer. The position of peak light intensity at the window structure of the active layer coincides with or very closely approaches the position of the active layer.

A semiconductor laser device comprises an optical fiber having an optical fiber grating formed therein, a semiconductor laser having an active layer with a single quantum well, for emitting laser light, and a coupling optical system for coupling the laser light emitted out of the semiconductor laser into the optical fiber. The coupling optical system can include a narrow-band filter for adjusting an incident angle of the laser light emitted out of the semiconductor laser. The optical fiber grating can have a reflection bandwidth wider than or substantially equal to a 3 dB bandwidth of the gain of the semiconductor laser or a spectrum full width at half maximum of the laser light of the semiconductor laser.

Semiconductor laser device and optical fiber amplifier

A semiconductor laser device includes a stacked structure. The stacked structure includes a first electrode, a substrate of a first conductivity type on the first electrode, a first cladding layer of the first conductivity type, an active layer, a second cladding layer of a second conductivity type opposite the first conductivity type, an insulating layer, and a second electrode. The second cladding layer includes at least first and second portions having thickness different from each other. The first portion is thicker than the second portion. The insulating layer is deposited on the second cladding layer but not on the first portion. The second electrode is electrically connected to the first portion. A product of a reciprocal of layer thickness and heat conductivity of the insulating layer is smaller than 4&times;10 W/(m K).

A semiconductor device and a photonic semiconductor device are disclosed wherein, if w is the thickness of a metal electrode layer covering a contact layer and current-unfed regions, D denotes the thickness of a plating layer on the metal electrode layer, the boundary between the contact layer and any one of the current-unfed regions is an origin, a direction from the origin into the device interior is a positive direction, and a direction from the origin toward any one of device facets is a negative direction, then a distance d between the origin and each facet of the plating layer satisfies (d/w)&lsqb;1&minus;w/(w&plus;D)&rsqb;<20.

Semiconductor device and photonic semiconductor device applying the semiconductor device

A method for simulating and analyzing two-dimensional current and light distributions of a semiconductor laser including an active layer, a cladding layer, and a light absorbing layer includes obtaining initial values of light distribution and carrier distribution, setting a bias condition, and performing current and light distribution analyses. The calculation of the initial value of the two-dimensional light distribution includes calculating a provisional absorption coefficient of the light absorbing layer from the refractive index of the cladding layer, the refractive index of the light absorbing layer, and the laser light wavelength; obtaining a solution in which the real part of the propagation constant of the wave equation is a maximum, using the provisional absorption coefficient; and repeating the calculation, using a sequential approximation method, until the absorption coefficient in the propagation constant equals the absorption coefficient in the original light absorbing layer. The propagation constant in the active layer is then larger than in a light absorbing region. Thus, the center of the light distribution is located in the active layer and the solution, specifying a laser oscillation mode, can be automatically derived without special judgment criteria.

Simulation method for semiconductor device

A method of fabricating a semiconductor laser device includes successively forming an active layer and upper cladding layers on a lower cladding layer, etching and removing portions except regions of the upper cladding layers where a current is to flow to form a stripe-shaped ridge structure, and forming a buffer layer comprising Al.sub.x Ga.sub.1-x As having an Al composition ratio x of 0 to 0.3 on a surface of the upper cladding layers exposed by the etching and forming a current blocking layer of first conductivity type Al.sub.y Ga.sub.1-y As having an Al composition ratio y of at least 0.5 on the buffer layer to bury portions of the upper cladding layers which are not removed by the etching process. Therefore, since the layer grown on the upper cladding layer exposed by etching of AlGaAs or GaAs having a low Al composition ratio (0-0.3), three-dimensional growth of and crystalline defects in the buffer layer are suppressed. Current leakage is suppressed, so that a semiconductor laser device having a low threshold current and a high efficiency is fabricated with a stable yield.

Semiconductor laser device and method of fabricating semiconductor laser

A semiconductor laser device includes semiconductor layers including an active layer and cladding layers sandwiching the active layer and current injecting structure for regulating a region in the active layer into which current is injected. A light confinement coefficient in the current injection region perpendicular to the active layer is smaller than a light confinement coefficient in the same direction of a saturable absorption region. The function of the saturable absorption region is enhanced and pulsation oscillation can be produced at a high power light output.

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Tokyo, Japan

Yasuaki Yoshida