Fuji Photo Film Company, Limited

Fujifilm Corporation

Fujinon Corporation

Showa Optronics Co., Ltd.

Masami Hatori

Shinichiro Sonoda

Masayuki Naya

Hiroshi Sunagawa

Nobuharu Nozaki

Hideo Miura

Kiichi Kato

Kazuhiko Nagano

Takashi Yamada

Kenji Matsumoto

Shinichi Shimotsu

Kiyoshi Kawai

Yuichi Teramura

Kenji Ohara

Isao Tsuruma

Kozi Kamiyama

Takuya Arichi

A semiconductor laser device with external resonator with stable longitudinal mode regardless of variation of drive current is disclosed. The device includes: a semiconductor light-emitting element having a pair of end faces with a light emitting section disposed therebetween, and an external resonator configured to oscillate light emitted from the semiconductor light-emitting element, the external resonator being formed by a resonator mirror disposed outside the semiconductor light-emitting element and one of the pair of end faces that is farther from the resonator mirror, wherein, as the semiconductor light-emitting element, a semiconductor light-emitting element having a structure which does not oscillate light emitted therefrom by itself is used. The device further includes a wavelength control element disposed in the optical path within the external resonator and configured to select a wavelength range of the light, and a driver circuit configured to perform fast modulation drive of the semiconductor light-emitting element.

Semiconductor laser with external resonator

A sensing system using a sensing element being constituted by a transparent body sandwiched by first and second reflectors one or each of which is in contact with a specimen, and exhibiting an absorption characteristic varying with the specimen. The first reflector is a partially transparent reflective, and the second reflector is completely reflective, or partially transparent reflective. A light injection unit injects light onto the first reflector, and a light detection unit detects the intensity of light outputted from the sensing element in response to the injection. The light injection unit has a wavelength stabilizing arrangement and injects laser light, or injects light at two wavelengths. In the latter case, the light detection unit detects the intensities of outputted light at the two wavelengths, and a calculation unit obtains the difference between the intensities.

Sensing system

In an optical tomography system, a polarization changing system which converts linearly polarized light too non-linearly polarized light is provided in at least one of a light source unit, an optical path from the light source unit to a light dividing system, the optical path of the measuring light from the light dividing system to an object, the optical path of the reflected light from the object to the combining system and the optical path of the reference light from the light dividing system to the combining system. The polarization changing system is, for instance, a polarization-preserving optical fiber which is disposed so that the direction of polarization of the linearly polarized light and the direction of axis of polarization of the linearly polarized light differ from each other.

Tomography system and method of adjusting quality of image obtained by optical tomography system

A polarization maintaining optical fiber, for guiding a measuring light beam, is provided within a probe. The probe is configured to be rotatable in the circumferential direction of the polarization maintaining optical fiber. A polarization direction rotator, for rotating the polarization direction of the measuring light beam that enters the polarization maintaining optical fiber accompanying rotation of the probe, is provided in order to maintain a state in which the polarization direction of the measuring light beam that enters the polarization maintaining optical fiber and the direction of the polarization axis of the polarization maintaining optical fiber are matched.

Optical coherence tomography system

An optical tomograph which irradiates and scans a measuring light beam onto a measurement target at a predetermined scanning frequency, to obtain a tomographic image of the measurement target is provided. A depolarizing unit, for varying the polarization state of light beams input thereto at a frequency equivalent to or higher than the scanning frequency, such that the light beam output therefrom becomes depolarized when averaged over time, is provided in the optical path of at least one of the measuring light beam, a reference light beam, and a reflected light beam between a light source unit and a combining unit.

Optical tomograph which obtains tomographic images irrespective of polarization direction of light beams

Light emitted from the light source unit is divided into measuring light and reference light. An optical path length of the measuring light or the reference light which has been divided by the light dividing means is adjusted. Interference light of the reflected light and the reference light is detected and a tomographic image of the object is obtained on the basis of the detected interference light. The optical path length is adjusted by a reflecting mirror which reflects the measuring light or the reference light radiated from the optical fiber, a first lens which is disposed between the reflecting mirror and the optical fiber and a second lens which collects the measuring light or the reference light made parallel by the first lens on the reflecting mirror and makes parallel the measuring light or the reference light reflected by the reflecting mirror.

Optical tomography system

A laser module includes: a chassis having a light-output window from which one or more laser beams are outputted; a hermetically sealed package which is fixed to the chassis; one or more semiconductor laser elements which are arranged in the hermetically sealed package, and emit the one or more laser beams; a transparent member which is arranged to cover the light-output window; an optical fiber which has a light-entrance end face, and is arranged outside the chassis so that the light-entrance end face is in contact with the transparent member; and an optical condensing system which is arranged inside the chassis, and makes the one or more laser beams pass through the transparent member and be condensed on the light-entrance end face. The transparent member and the optical fiber are detachably attached to the chassis.

Laser module having detachable transparent member covering light-output window

An optical probe includes a tubular outer envelope and a optical fiber which extends in the longitudinal direction of the outer envelope inside the outer envelope. By fixing a light deflecting element to the optical fiber and rotating the optical fiber by a driver, the light deflecting element is rotated. A protective member which has a higher resistance to wear than the outer peripheral surface of the optical fiber is fixed to a part of the outer peripheral surface of the optical fiber in a position near the front end of the optical fiber and is borne for rotation by a bearing portion on the probe outer envelope.

Optical probe and optical tomography system

A light source module includes at least one light source, first optical waveguide which causes light entering therein from a light inlet end face to emanate from a light outlet end face, and an inlet optical system which collects light emitted from the light source and couples it to the light inlet end face of the first optical waveguide. The light inlet end face of the first optical waveguide is larger than the light outlet end face thereof in cross-sectional area of the core.

Light source module

A wavelength selecting optical element such as a narrow band-pass filter or the like is provided between a semiconductor laser and a light wavelength conversion element formed of a bulk-shaped wavelength conversion crystal. The wavelength selecting optical element selects a wavelength of a laser beam which is to be reflected by an end surface of the light wavelength conversion element to be fed back to the semiconductor laser.

Light scanning and recording apparatus

A light wavelength converting element which can reduce an amount of light fed-back to a semiconductor laser. The light wavelength converting element converts a wavelength of a fundamental wave which enters from a first end surface side of an optical waveguide to thereby emit a converted wavelength wave from a second end surface side thereof. The second end surface is inclined with respect to the side surface of the optical waveguide. Also provided is a wavelength stabilized laser having a semiconductor laser, a device which feeds a laser beam emitted from the semiconductor laser back to the semiconductor laser, and a band-pass filter. An optical length between the semiconductor laser and the device is made to be longer than a coherent length of the semiconductor laser, thus improving linearity of a current vs. light output characteristic. Further, a light wavelength converting unit and a light wavelength converting module are provided in which, since an LD-SHG unit formed by a semiconductor laser and a light wavelength converting element is hermetically sealed in a package, the LD-SHG unit can be manufactured easily and has excellent stability over time.

Light wavelength converting system

A semiconductor laser module is formed by directly bonding a semiconductor laser, which has a wavelength tuning mechanism, and an optical wavelength conversion element which exits laser beam of the second harmonic with the wavelength of the exited laser beam being the fundamental wave. A center wavelength of stimulated emission of the semiconductor laser is tunable, and is locked so as to coincide with a phase matching wavelength of the optical wavelength conversion element. The semiconductor laser and the optical wavelength conversion element are directly bonded together at an end surface portion of an optical wavelength of the optical wavelength conversion element.

Semiconductor laser module and method for forming semiconductor laser module

The present invention provides a light wavelength conversion module in which an output light amount of a light wavelength conversion element increases monotonically as a driving current of a semiconductor laser increases. The light wavelength conversion module includes the semiconductor laser having an external resonator provided with a narrow band-pass filter, and the light wavelength conversion element for converting a laser beam emitted from the semiconductor laser to a second harmonic wave. A semiconductor laser, which emits a laser beam including a plurality of longitudinal mode spectra within an acceptable wavelength band of the light wavelength conversion element, is used in the light wavelength conversion module.

Light wavelength conversion module

A surface plasmon sensor is formed by a dielectric block, a metal film which is formed on one face of the dielectric block and is brought into contact with a sample, a light source emitting a light beam, an optical system which causes the light beam to enter the dielectric block so that the light beam is reflected in total reflection at the interface of the dielectric block and the metal film and various angles of incidence of the light beam to the interface of the dielectric block and the metal film including an angle of incidence at which surface plasmon is generated can be obtained, and a photodetector which is able to detect the intensity of the light beam reflected in total reflection from the interface for the various angles of incidence. A laser provided with an oscillation wavelength stabilizing system for stabilizing the wavelength at which the laser oscillates is used as the light source.

Surface plasmon sensor

An optical wavelength conversion system includes an optical waveguide type optical wavelength conversion element having periodic domain reversals, and a semiconductor laser which generates a laser beam which is caused to enter the optical wavelength conversion element as a fundamental wave. A part of the laser beam is split by a beam splitter upstream of the optical wavelength conversion element, and the split part of the laser beam is reflected by a mirror and fed back to the semiconductor laser. A narrow band pass filter is disposed between the beam splitter and the mirror.

Growing community of inventors

Kanagawa-ken, Japan

Masami Hatori