An optical attenuator has a male connector, a female connector that is spaced apart from the male connector in a front-rear direction, a holder, and an attenuating member. The holder extends in the front-rear direction and has two opposite ends respectively connected to the male and female connectors. The holder is formed with a mounting groove which extends in the front-rear direction. The attenuating member extends through the mounting groove, and has two opposite ends respectively inserted into the male and female connectors.

Optical cross connects and methods for use therewith are described herein. In an embodiment, an optical cross connect includes first and second mirror arrays, first and second light sources that respectively emit first and second color coded light beams (e.g., each of which includes red, green and blue light), and first and second cameras configured to respectively capture first and second color images of the first and second color coded light beams reflected respectively from the first and second mirror arrays. The optical cross connect also includes a controller configured to perform closed loop feedback control of the first and second mirror arrays, based on the first and second color images, when the controller controls how optical signals are transferred between individual optical fibers in a first bundle of optical fibers and individual optical fibers in a second bundle of optical fibers.

A semiconductor photodetector comprising a closed loop configured to receive light from an external source adapted to trap light within said closed loop until absorption by the semiconductor.

A differential mode attenuation compensator includes a first multi-mode optical fiber and a third multi-mode optical fiber in which a plurality of propagation modes propagate in a wavelength of a propagating optical signal; and a second multi-mode optical fiber including a core and a clad and arranged with a central axis aligned between the first multi-mode optical fiber and the third multi-mode optical fiber, in which each loss in the plurality of propagation modes is different in the first multi-mode optical fiber and the third multi-mode optical fiber.

An integrated optical device includes: a housing; a liquid-crystal optical power attenuator, an optical splitter, and an optical power monitor housed inside the housing; and first and second optical fibers housed inside the housing. The first optical fibers input an optical signal from outside the housing to the optical power attenuator. In a polarized state, the optical power attenuator attenuates the optical signal from the first optical fibers. The second optical fibers output the attenuated optical signal from the optical power attenuator to outside the housing. The optical splitter generates a split signal by splitting at least one of: the optical signal input to the optical power attenuator from the first optical fibers, and the attenuated optical signal propagated from the optical power attenuator to the second optical fibers. The optical power monitor receives the split signal and detects a power of the split signal.

The present disclosure relates to a polarity detector for detecting polarity of a patch cord, that is capable of sequentially inputting an optical signal into channels of a connector of the patch cord, receiving the optical signal being output, and thereby discerning the polarity of the patch cord quickly and precisely. Particularly, the present disclosure is characterized to spectrally output the optical signal from the light source as a plurality of unit optical signals, and to selectively block or pass the spectrally output plurality of unit optical signals, by heat, and thereby effectively inputting the optical signal into each channel of the connector.

A variable wavelength filter includes: an input optical fiber; a diffraction grating that disperses input light from the input optical fiber; a variable mirror that has a reflective surface, wherein an angle of the reflective surface is adjustable, the variable mirror reflects the input light dispersed by the diffraction grating, the input light reflected by the variable mirror passes through a normal optical path, the input light that passes through the normal optical path has a wavelength band defined based on the angle of the reflective surface, and the defined wavelength band has a center wavelength corresponding to the angle of the reflective surface; an output optical fiber that outputs a portion of the input light that has passed through the normal optical path; and an optical detector disposed on a propagation path of the input light from the input optical fiber to the output optical fiber.

An optical transmission device controls driving of a mirror that adjusts an attenuation amount of a VOA and a transmission frequency of a TOF. The device acquires an adjustment amount of a reference voltage in which the intensity of output light becomes a target at detecting a change in the attenuation amount. The device calculates a deviation of an attenuation amount by using a difference between the reference frequency and the adjusted frequency specified from the characteristic of the mirror. The device calculates a deviation of an attenuation amount from a relationship at detecting a change in a new attenuation amount. The device calculates an adjustment amount by using a difference between the voltage of the reference frequency specified from the characteristic and the voltage of the frequency that is after deviation, adds the adjustment amount to the reference voltage, and sets the result.

A polishing apparatus capable of accurately measuring a film thickness by regulating a quantity of light illuminating a wafer is disclosed. The polishing apparatus includes: a light source; an illuminating fiber having distal ends arranged at different locations in the polishing table; and a light-receiving fiber having distal ends arranged at the different locations in the polishing table. The illuminating fiber includes a first illuminating fiber and a second illuminating fiber. A first dimmer is attached to the first illuminating fiber and the second illuminating fiber, and a second dimmer is attached to at least one of the first illuminating fiber and the second illuminating fiber.

Disclosed are a collimator for reducing noise of a scanned image and an imaging catheter system comprising the same. The disclosed noise attenuation collimator comprises: a transparent tube having a diameter larger than a cladding diameter of double-clad fiber, wherein a coatingless region of the double-clad fiber is inserted into the transparent tube; and a first resin layer which is applied to an exterior of the transparent tube and has a refractive index lower than the refractive index of the transparent tube.