Fuji Xerox Co., Ltd.

Masahiro Yoshikawa

Masateru Yamamoto

Takashi Kondo

Akira Sakamoto

Hideo Nakayama

Nobuaki Ueki

Hiromi Otoma

Osamu Ueno

Kazutaka Takeda

Tomoaki Kojima

Yasuaki Miyamoto

Kazuyuki Matsushita

Kohei Yukawa

Seiya Omori

Kohtaro Handa

An image forming apparatus includes an image forming device forming an image on a recording medium; and a light source that, after the image has been formed by the image forming device, irradiates the recording medium with light to fix the image on the recording medium, while the recording medium moves relatively in a predetermined movement direction. The light source includes a current supply section, a light emitting section, and a current output section. Current for light emission is supplied to the current supply section. The light emitting section includes light emitting elements that are disposed two-dimensionally. At least the light emitting elements provided side by side in the movement direction are electrically connected in parallel. The current output section outputs the current that has passed through the light emitting section. The current supply section and the light emitting section are provided side by side in the movement direction.

Image forming apparatus having fixing unit with improved light emission, fixing device, and drying device

A vertical cavity surface emitting laser that includes: a substrate; a first reflector of a first conductive type formed on the substrate; an active region formed on the first reflector; a second reflector of a second conductive type formed on the active region; and a current confining layer formed between the first reflector and the second reflector; and a metallic electrode that is formed on the second reflector, and is electrically connected to the second reflector. A conductive region with an anisotropy where a length in a longitudinal direction is different from a length in a short direction is formed in the current confining layer, and an opening defining a beam aperture is formed in the metallic electrode, and a diameter of the opening in the longitudinal direction is smaller than the length of the conductive region in the longitudinal direction.

Vertical cavity surface emitting laser, vertical cavity surface emitting laser device, and optical transmission device

A vertical cavity surface emitting laser that includes: a substrate; a first semiconductor multilayer reflector; an active region; a second semiconductor multilayer reflector; a columnar structure formed from the second semiconductor multilayer reflector to the first semiconductor multilayer reflector; a current narrowing layer formed inside of the columnar structure and having a conductive region surrounded by an oxidization region; a first electrode formed at a top of the columnar structure, electrically connected to the second semiconductor multilayer reflector and defining a beam window; a first insulating film comprised of a material with a first refractive index and formed on the first electrode to cover the beam window; and a second insulating film comprised of a material with a second refractive index and formed on the first insulating film, of which a radius is smaller than a radius of the conductive region.

Vertical cavity surface emitting laser, vertical cavity surface emitting laser device, optical transmission device, and information processing apparatus

A surface emitting semiconductor laser includes: a substrate; a first semiconductor multilayer reflection mirror of a first conduction type; an active region; a second semiconductor multilayer reflection mirror of a second conduction type; a first selectively oxidized layer that is formed in one of the first and second semiconductor multilayer reflection mirrors and includes a first oxidized region selectively oxidized, and a first conductive region surrounded by the first oxidized region; and a second selectively oxidized layer that is formed in one of the first and second semiconductor multilayer reflection mirrors and includes a second oxidized region selectively oxidized, and a second conductive region surrounded by the second oxidized region. A first semiconductor layer next to the first selectively oxidized layer has an Al composition greater than that of a second semiconductor layer next to the second selectively oxidized layer, the first conductive region having a size smaller than that of the second conductive region.

Surface emitting semiconductor laser and method for fabricating the same

An optical module includes a mounted member, a surface optical device and a positioning portion. The mounted member includes an inserted portion. The surface optical device includes a substrate, an optical axis, and an insertion portion. The optical axis is provided in a direction perpendicular to the substrate. The insertion portion has a step surface that is inserted into the inserted portion of the mounted member in a direction perpendicular to the optical axis so as to position the optical axis. The positioning portion is provided in the mounted member and positions an optical transmission member so that the optical transmission member is optically coupled to the surface optical device.

Optical module, optical transmission device, and surface optical device

A VCSEL includes a first conductivity-type first semiconductor mirror layer on a substrate, an active region thereon, a second conductivity-type second semiconductor mirror layer thereon, and a current confining layer in proximity to the active region. A mesa structure is formed such that at least a side surface of the current confining layer is exposed. The current confining layer includes a first semiconductor layer having an Al-composition and a second semiconductor layer having an Al-composition and being formed nearer to the active region than the first semiconductor layer does. Al concentration of the first semiconductor layer is higher than that of the second semiconductor layer. When oscillation wavelength of laser light is &#x3bb;, optical thickness being sum of the thickness of the first and second semiconductor layers is &#x3bb;/4. The first and second semiconductor layers are selectively oxidized from the side surface of the mesa structure.

VCSEL, manufacturing method thereof, optical device, light irradiation device, data processing device, light sending device, optical spatial transmission device, and optical transmission system

Provided is a VCSEL that includes a first semiconductor multilayer film reflective mirror of a first conductivity type formed on a substrate and having a first impurity concentration; an active region formed thereon; a second semiconductor multilayer film reflective mirror of a second conductivity type formed on and close to the active region and having a second impurity concentration; a third semiconductor multilayer film reflective mirror of the second conductivity type formed thereon and having a third impurity concentration being higher than the second impurity concentration; and a fourth semiconductor multilayer film reflective mirror of the second conductivity type formed thereon and having a fourth impurity concentration being higher than the second impurity concentration. The reflective mirrors include a pair of a low-Al semiconductor layer and a high-Al semiconductor layer. The Al-composition of the low-Al semiconductor layer in the second reflective mirror is higher than that of the fourth mirror.

Vertical-cavity surface-emitting laser, module, optical transmission device, optical transmission system, free space optical communication device, and free space optical communication system

Provided is a VCSEL that includes: a first semiconductor multilayer film reflective mirror of a first conductivity type formed on a substrate; an active region formed thereon; a current confining layer of a second conductivity type formed thereon; a second semiconductor multilayer film reflective mirror of the second conductivity type formed thereon; and a third semiconductor multilayer film reflective mirror of the second conductivity type formed thereon. The reflective mirrors include a pair of a high refractive index layer and a low refractive index layer. The impurity concentration of the second reflective mirror is higher than that of the third reflective mirror. The band gap energy of the high refractive index layer in the second reflective mirror is greater than the energy of the wavelength of a resonator formed of the first reflective mirror, the active region, the current confining layer, the second reflective mirror, and the third reflective mirror.

Vertical-cavity surface-emitting laser, module, optical transmission device, free space optical communication device, optical transmission system, and free space optical communication system

A VCSEL includes a first distributed Bragg reflector (DBR) of a first conductivity type formed on a substrate and including at least one semiconductor layer to be oxidized, an active region having a column shaped structure and formed on the first DBR, and a second DBR of a second conductivity type. At least one hole starting from a surface of the first DBR and reaching the at least one semiconductor layer to be oxidized is formed in the first DBR outside of a column shaped structure of the second DBR. An oxidized region is formed in the semiconductor layer to be oxidized by selectively oxidizing from a side surface of the hole. In the first DBR, a first current path is formed by a conductive region surrounded by the oxidized region, and a second current path is formed by a conductive region not surrounded by the oxidized region.

VCSEL, optical device, light irradiation device, data processing device, light source, free space optical communication device, and optical transmission system

A VCSEL includes a substrate, a first semiconductor multilayer of a first conductivity-type, an active layer, a second semiconductor multilayer of a second conductivity-type, a contact layer, each of the layers stacked on the substrate. The second semiconductor multilayer constitutes a resonator together with the active layer and the first semiconductor multilayer. A metal layer is formed on the contact layer. The metal layer includes an opening portion that defines a region that emits laser light. When oscillation wavelength of the laser light is &#x3bb;, optical thickness T of the contact layer and a top layer of the second semiconductor multilayer that contacts with the contact layer is smaller than &#x3bb;/4.

VCSEL, manufacturing method thereof, module, light sending device, optical spatial transmission device, light sending system, and optical spatial transmission system

A surface emitting semiconductor laser array includes multiple light-emitting portions arranged in a one-dimensional or two-dimensional array, each of the light-emitting portions including, on a substrate, an active region and a current funneling portion between first and second reflection mirrors, and a light-emission aperture above the second reflection mirror, laser beams being simultaneously emitted from the multiple light-emitting portions. At least one of the multiple light-emitting portions has a near field pattern different from those of other light-emitting portions.

Surface emitting semiconductor laser array and optical transmission system using the same

A surface emitting semiconductor laser is formed from a substrate having a first mirror formed thereon. The first mirror includes semiconductor layers of a first conductivity type. A second mirror is formed over the substrate and includes semiconductor layers of a second conductivity type. An active region is disposed between the first and second mirrors, with a current confining layer being disposed between the first and second mirrors. A compound semiconductor layer is formed over the second mirror and an electrode is formed on the compound semiconductor layer. A protective film covers the compound semiconductor layer and partially covers the electrode. The electrode is formed by a lift-off process and uses an opening-pattern that is formed by plasma ashing.

Surface emitting semiconductor laser

The present invention provides a surface emitting semiconductor laser, comprising: a semiconductor substrate having sequentially layered thereon a lower multi-layer mirror, an active layer region, and an upper multi-layer mirror that, together with the lower multi-layer mirror, contributes to the formation of a cavity; an upper electrode disposed on an upper layer of the upper multi-layer mirror and provided with an aperture that forms an emission region of a laser beam generated at the active layer region; and a current confinement portion disposed between the upper electrode and the lower multi-layer mirror and provided with an aperture that forms a current path; wherein an aperture diameter of the upper electrode and an aperture diameter of the current confinement portion are determined such that a difference between an optical loss of the cavity in a higher-order lateral mode of the laser beam and an optical loss of the cavity in a fundamental lateral mode of the laser beam becomes a value in the vicinity of a maximum value, and the higher-order lateral mode is suppressed, and at least one of the aperture formed in the upper electrode and the aperture of the current confinement portion is formed into a two-fold symmetrical configuration having long and short axes with respect to arbitrary two axial directions orthogonal to each other in a plane.

A surface emitting semiconductor laser that is easy to manufacture and has a high-intensity fundamental lateral mode optical output power. The surface emitting semiconductor laser has a semiconductor substrate on which are sequentially laminated a lower n-type DBR layer, an active layer region, an upper p-type DBR layer, a p-side electrode that is an upper layer of the upper n-type DBR layer and functions as an upper electrode provided with an aperture that forms an emission region for a laser beam, and a current confinement portion formed by oxidization. On the basis of the reflectance of a cavity in a region corresponding to the p-side electrode, a metal aperture diameter (W ) of the aperture and a diameter (W ) of the current confinement portion are determined such that the difference between an optical loss of a cavity in a higher-order lateral mode of a laser beam and an optical loss of a cavity in a fundamental lateral mode of a laser beam becomes larger.

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Kanagawa, Japan

Masahiro Yoshikawa