摘要:
A laser diode that emits light of a predetermined wavelength, an optical fiber that propagates the light emitted from the laser diode, and a transmission liquid crystal variable optical attenuator that is arranged on an optical axis of the light between the laser diode and the optical fiber and attenuates light intensity of the light are arranged inside a housing. A coupling lens couples the light emitted from the laser diode to an incidence end of the optical fiber. An isolator prevents return light from the optical fiber side.
摘要:
A liquid crystal variable wavelength filter unit and its driving method applicable for a Wavelength Division Multiplexing (WDM) communication system and an optical network using an optical fiber. The liquid crystal variable wavelength filter unit (130) includes a band pass filter (111) configured of a dielectric multi-layered film inclined by a predetermined angle of a between a first liquid crystal beam deflector (101) and a second liquid crystal beam deflector (103) and held between a first wedge prism (121) and a second wedge prism (123). The first drive device (141) is connected to the first liquid crystal beam deflector (101), and the second drive device (143) is connected to the second liquid crystal beam deflector (103). The wavelength is selected by the liquid crystal beam deflector by making the outgoing angle variable with respect to the band pass filter.
摘要:
The liquid crystal display device comprises a liquid crystal cell with liquid crystals sealed thereinbetween, sandwiched between two transparent substrates having an electrode on each of the inner surfaces thereof facing each other, a first reflective polarizing film disposed on the visible side of the liquid crystal cell, a second reflective polarizing film disposed on the side of the liquid crystal cell, opposite from the visible side, and a light absorption film disposed on the side of the second reflective polarizing film, opposite from the visible side. The first reflective polarizing film as well as the second reflective polarizing film is a polarizing sheet reflecting a light linearly polarized in the direction orthogonal to the transmission axis thereof. A light absorption film and/or a backlight may preferably be disposed under the second reflective polarizing film. Further, an absorption-type polarizing film or a light diffusion layer may preferably be disposed on the visible side of the first reflective polarizing film.
摘要:
A laser light source according to the present invention includes a laser element that outputs a fundamental wave; a wavelength conversion element into which the fundamental wave is input and that converts at least a part of the fundamental wave input therein to a converted wave having a wavelength shorter than the wavelength of the fundamental wave; a waveguide that attenuates a component of the fundamental wave included in an output wave from the wavelength conversion element; and a diffraction grating that is formed on the waveguide and feeds back the fundamental wave output from the wavelength conversion element to lock the wavelength or the frequency of the fundamental wave output from the laser element. The diffraction grating is formed at a position determined taking into account an amount by which the fundamental wave is attenuated in the waveguide.
摘要:
In a light source device for combining light waves with at least three wavelengths and outputting thus combined light waves, an optical system element and an electrical system element are formed on a semiconductor substrate, thereby eliminating the necessity of optical members such as an optical connector, and saving space to place the optical members as well as reducing arrangement spacing. In addition, the space necessary for wiring in an electrical circuit is reduced. Therefore, an integration degree of each of the elements, the optical system element and the electrical system element, is enhanced. The optical system element and the electrical system element are formed in layers on the same conductor substrate, thereby reducing the area that is required in configuring a parallel establishment of the optical system element and the electrical system element.
摘要:
A wavelength conversion device includes a base substrate having a transparent electrode on one surface thereof and a ferroelectric single crystal substrate provided with an optical waveguide. The ferroelectric single crystal substrate has an insulating film formed on one surface and is bonded to the base substrate such that the insulating film faces the transparent electrode.
摘要:
For statically driving a liquid-crystal optical-modulation device, an alternating electric field produced by a drive signal is applied to a liquid crystal included therein. In a first period in which the alternating electric field has a first polarity, the drive signal is pulse-width modulated based on a first ON-voltage and a first OFF-voltage. In a second period in which the alternating electric field has a second polarity, the drive signal is pulse-width modulated based on a second ON-voltage and a second OFF-voltage.
摘要:
A variable optical attenuator includes an optical fiber on an incident side and an optical fiber on an emission side; a polarization rotator element that includes a liquid crystal layer and a pair of substrates that are arranged in such a manner that the liquid crystal layer is sandwiched between the substrates; and a Savart plate that is arranged between the optical fibers and the polarization rotator element. In the polarization rotator element, rotation of a polarizing direction is controlled by controlling a birefringence characteristic of liquid crystal, which is controlled by controlling alignment of the liquid crystal layer.
摘要:
A variable optical attenuator includes an optical fiber on an incident side and an optical fiber on an emission side; a polarization rotator element that includes a liquid crystal layer and a pair of substrates that are arranged in such a manner that the liquid crystal layer is sandwiched between the substrates; and a Savart plate that is arranged between the optical fibers and the polarization rotator element. In the polarization rotator element, rotation of a polarizing direction is controlled by controlling a birefringence characteristic of liquid crystal, which is controlled by controlling alignment of the liquid crystal layer.
摘要:
A liquid crystal display device is structured in such a manner that plural of liquid crystal display panels each comprised of a liquid crystal layer provided between a pair of transparent substrates which have electrodes disposed on each facing inner surface, and a reflection-type polarizing film is disposed at least on the top surface of the plural liquid crystal display panel, or between the liquid crystal display panels, or on the lowest surface of the plural liquid crystal display panel. By controlling a reflection state and a transmission state through the reflection-type polarizing film with electric voltage applied on the liquid crystal layer of the liquid crystal display panel, a display which represents the opening and closing of a metallic shutter is made possible.