摘要:
A semiconductor laser that selectively performs oscillations in different polarization modes has first and second laser regions on a substrate. The first laser region exhibits a gain spectrum in which one polarization mode is dominant and the second laser region exhibits a gain spectrum in which a different polarization mode is dominant. Current injected independently into the each laser region causes polarization mode oscillation competition. One of the different polarization mode oscillations is selected by, for example, injecting a minute modulated current into at least one of the first and second laser regions.
摘要:
In an optical operation apparatus, a light source emits a light intensity-modulated on the basis of a first electrical signal. A modulating device receives the light from the light source and intensity-modulates the light on the basis of the first signal, and a photoelectric converting device converts the light modulated by the modulating device into a second electrical signal. These functions are carried out by any of a number of different arrangements of filter elements, and electro-optical or acoustico-optical devices can be used for intensity modulation.
摘要:
A variable wavelength light source is provided with a laser of which the oscillating state can be changed over between two oscillating states accompanied by a change of an oscillation wavelength, and an optical selection element for selecting an output light in one of the two oscillating states of the laser. The optical selection element is capable of changing over which of the output lights in the two oscillating states of the laser is to be selected. Also, by using a laser in which the oscillation wavelength in the respective oscillating states can be changed, the wavelength variation ranges in the both oscillating states can be used.
摘要:
A method of making and an element having a light waveguide in which the input-output area through which light is input or output is made into a light waveguide of a high threshold value of optical damage formed by outside diffusion of lithium oxide or by ion exchange and the optically functional portion in which the waveguide light is modulated or deflected by extraneous action is made into a light waveguide formed by diffusion of a metal of high light modulation or light deflection efficiency.
摘要:
An optical fiber apparatus includes an optical fiber, and a demultiplexing/multiplexing unit for demultiplexing or multiplexing at least a light wave of at least a wavelength with a sufficiently narrow wavelength spectrum that is determined by a resolving power thereof, such as a Fabry-Perot etalon. The demultiplexing/multiplexing unit is provided or formed directly on at least an end face of the optical fiber. An optical detector array including a plurality of optical detectors for detecting demultiplexed light waves may be provided on a light emergence surface of of the demultiplexing/multiplexing unit.
摘要:
A polarization-mode selective semiconductor laser includes a semiconductor laser structure including an active layer for generating gain spectra for the first and second different polarization modes and a diffraction grating formed with a uniform pitch over the laser structure. The laser structure includes a first DFB reflector portion with a first channel stripe and a second DFB reflector portion with a second channel stripe connected to the first stripe channel. The first DFB reflector portion and the second DFB reflector portion is serially arranged in a cavity direction of the laser. The first and second stripe channels are bent relative to each other such that a Bragg wavelength for the first polarization mode is coincident with a gain peak wavelength for the first polarization mode in the first DFB reflector portion, to make the first polarization mode dominant in the first DFB reflector portion, and that a Bragg wavelength for the second polarization mode is coincident with a gain peak wavelength for the second polarization mode in the second DFB reflector portion, to make the second polarization mode dominant in the second DFB reflector portion.
摘要:
A diffraction grating includes first regions for mainly reflecting first polarized light and second regions for mainly reflecting second polarized light. The first regions and the second regions are alternately arranged in a light propagation direction in a variety of manners to appropriately set its polarization-mode dependency according to need. An optical semiconductor device includes a semiconductor substrate, a laser structure and that diffraction grating formed in the laser structure. The laser structure is a distributed feedback semiconductor laser structure or a distributed Bragg reflector semiconductor laser structure formed on the semiconductor substrate.
摘要:
A polarization-independent wavelength demultiplexing apparatus for demultiplexing a light beam of at least one predetermined wavelength, includes a first demultiplexer for demultiplexing the light beam at a predetermined wavelength to obtain a component of the light beam in a first polarization state and second demultiplexer for demultiplexing the light beam at the predetermined wavelength to obtain a component of the light beam in a second polarization state, different from the first polarization state. The first demultiplexer and the second demultiplexer are arranged in a serial manner or in a parallel manner with respect to light transmitted through the demultiplexing structure.
摘要:
A first light waveguide is formed, and second and third light waveguides are respectively connected to the first light waveguide at first and second positions. A first coupler for effecting tight branching and/or combining is arranged near the first position, and a second coupler for effecting light branching and/or combining is arranged near the second position. An optical amplifier is arranged on the first light waveguide between the first and second positions for compensating for a light loss of a light wave caused by each of the first and second coupler.
摘要:
An optical device includes a channel or three-dimensional light waveguide for propagating a light wave therethrough and an optical coupler for effecting at least one of branching and combining of the light wave by splitting a wavefront of a field distribution of the light wave. The coupler is produced by forming a portion whose reflection factor is different from the waveguide, extending in a vertical direction of the waveguide. The portion of different reflection factor is formed deep enough in the vertical direction to perform the splitting of the wavefront of the field distribution of the light wave with respect to at least a horizontal or lateral direction, or the portion of different reflection factor is formed at a flat portion of the waveguide.