Fujikura Limited

Shinichi Sakamoto

Norihiro Ishikura

Shohei Kumeta

Yutaka Yamaguchi

Yasuto Chiba

Wataru Kiyoyama

Kazuhiro Goi

Yohei Kasai

Yasuhiro Mashiko

Takashi Hasunuma

Kensuke Shima

Kohei Matsumaru

Hideyuki Wada

Tatsuya Kishi

Susumu Nakaya

Yasuo Nakanishi

Sho Namiki

A laser device includes at least one light source; a delivery fiber configured to propagate laser light launched from the light source; a monitor fiber optically coupled to the delivery fiber and configured to propagate a part of the light propagating in a direction opposite to a propagation direction of the laser light in the delivery fiber, and a light receiving unit configured to receive the light propagated by the monitor fiber. The light receiving unit is configured to detect first light included in a wavelength band of visible light.

Laser device

An optical device includes a first fiber including a first reflector, a second fiber including a second reflector, and an amplifying fiber that has a normalized frequency that is greater than or equal to 5.13 and is wound so as not to intersect on one plane. The amplifying fiber includes an outer section wound in a circular manner. The amplifying fiber includes an inner section having first arc portions and wound such that at least two of the first arc portions have a radius of curvature in which a higher-order mode that is higher than an LP11 mode has loss. The amplifying fiber includes a first end connected to the first fiber and disposed on an inside of the amplifying fiber. The amplifying fiber includes a second end connected to the second fiber.

Optical device and fiber laser apparatus

A laser device includes at least one light source; a delivery fiber that is configured to propagate of laser light emitted from the light source; and a first light detection unit and a second light detection unit configured to detect a part of light propagating in a direction opposite to a propagation direction of the laser light through the delivery fiber. The first light detection unit detects first light included in a wavelength band of visible light. The second light detection unit detects second light included in a wavelength band of near-infrared light.

A fiber laser system including: fiber laser units each including an excitation light source; a combiner that combines laser beams generated by the respective fiber laser units; and a controller that controls strength of a driving current supplied to each of the excitation light sources and reduces a difference in power between the respective laser beams.

Fiber laser system and method for controlling same

A photodetection device including: first optical fibers; a second optical fiber; an optical combiner having: an end face connected to an end face of each of the first optical fibers; and another end face connected to an end face of the second optical fiber; a first photodetector that detects an intensity of light propagating through at least one of the first optical fibers; a second photodetector that detects Rayleigh scattering of light propagating through the second optical fiber; and a calculator that calculates the intensity of light propagating in a predetermined direction through the first optical fibers or the second optical fiber, from a result of detection by the first photodetector and a result of detection by the second photodetector.

Photodetection device and laser device

A fiber laser device includes a pumping light source, an amplifying fiber, an input side fiber fusion-spliced on an input side of the amplifying fiber and formed with a HR-FBG, an output side fiber fusion-spliced on an output side of the amplifying fiber and formed with an OC-FBG having a reflectivity smaller than that of the HR-FBG, an output end, and a mode filter, wherein the input side fiber or an intermediate fiber disposed between the amplifying fiber and the input side fiber is fusion-spliced with the amplifying fiber via a fusion splice portion, and at least a portion of the mode filter is disposed in a region between the fusion splice portion and a position separated from the fusion splice portion by a coherence length of beating caused by mode interference of signal light propagating in the amplifying fiber.

Fiber laser device

A laser device includes: a laser unit that outputs laser light; an output end that launches the laser light; a first fusion splice portion; and a second fusion splice portion. In each of the first fusion splice portion and the second fusion splice portion, two multi-mode fibers are fusion-spliced. Each of the two multi-mode fibers include a core through which the laser light propagates and a cladding that surrounds the core. The first fusion splice portion is disposed closer to the laser unit than is the second fusion splice portion. At least a part of the core in the first fusion splice portion contains a dopant that is the same type as a dopant contained in the cladding in the first fusion splice portion for decreasing a refractive index.

Laser device and method for manufacturing laser device

A fiber laser device includes: an amplifying fiber; a delivery fiber in which laser light that has been outputted from the amplifying fiber is guided; and a Raman filter that reflects part of Raman scattered light that is generated by stimulated Raman scattering caused to the laser light.

Fiber laser device, production method for fiber laser device, and setting method

A laser device includes: a light source including laser diodes; a processor that holds: a maximum current value of a driving current applied to the laser diodes, and a maximum power value of a power of light emitted from the light source; and a memory, coupled to the processor, that stores a relationship between a magnitude of the driving current, a magnitude of the power of the light, and a degree of deterioration of the light source. The processor further refers to the memory and estimates the degree of deterioration from the maximum current value and the maximum power value.

Laser device, and method for estimating degree of deterioration of light source of laser device

A light detection device includes: a first optical fiber including a first core surrounded by a first cladding; a second optical fiber including a second core surrounded by a second cladding; a first cladding mode stripper provided outside the first cladding; a first light detector; and a second light detector. The second core has a diameter larger than a diameter of the first core and is connected to the first core. In a longitudinal direction of the first optical fiber, the first light detector is disposed on one side of the first cladding mode stripper and the second light detector is disposed on another side of the first cladding mode stripper.

Light detection device and laser device

Provided is a micro optical circuit including a first micro optical waveguide and a second micro optical waveguide with a boundary face therebetween, in which the height of the first and second micro optical waveguides is different from each other, and the side faces of the first micro optical waveguide are connected to the side faces of the second micro optical waveguide at first and second connection points in a plan view. An intersection between the boundary face and the center line equidistant from the two side faces of the second micro optical waveguide is present in a region between a first straight line and a second straight line in a plan view, the first straight line passing through the first and second connection points, the second straight line crossing the second micro optical waveguide so as not to cross the first micro optical waveguide.

Micro optical circuit and optical mode converter

A double mirror (Mi) is made of a first mirror (Mi) that is mounted on a top surface of a base plate (B) and a second mirror (Mi) that is mounted on a top surface of the first mirror (Mi). The first mirror (Mi) has a reflective surface (S) for reflecting an input beam. The second mirror (Mi) has a reflective surface (S) for reflecting the input beam which has been reflected by the reflective surface (S).

Light guide device, manufacturing method, and laser diode module

An optical device includes a window glass plate with which a window of a lid section is provided and which is connected to the lid section via a solder layer so that an internal space of the optical device is hermetically sealed. The solder layer has a void which is isolated from an external space and an internal space of the optical device.

Optical device and method for manufacturing optical device

In a laser devicein which a laser moduleis mounted on a heat sink, a base plateof the laser moduleis fixed onto a mounting surfaceof the heat sinkin such a manner that a peripheral partis fixed to the heat sinkwith screws. The elastic force of the base platecauses stress in the direction toward the mounting surfaceon the central partof the base platesurrounded by the peripheral part

Laser device and laser device manufacturing method

In order to reduce a high frequency loss of a substrate-type optical waveguide without facilitating, in a low frequency domain, a reflection by an entrance end of a traveling-wave electrode, the substrate-type optical waveguide includes a coplanar line, provided on an upper surface of an upper cladding, which includes (i) a traveling-wave electrode connected to a P-type semiconductor region and (ii) an earth conductor connected to an N-type semiconductor region. The traveling-wave electrode and the earth conductor are provided so that a distance D therebetween decreases as a distance from an entrance end of the traveling-wave electrode increases.

Growing community of inventors

Sakura, Japan

Shinichi Sakamoto