Abstract:
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.
Abstract:
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.
Abstract:
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.
Abstract:
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.
Abstract:
A pump unit can achieve significant size reduction while maintaining the performance thereof. Micropumps are arranged in a lattice pattern with rows and columns, and a discharge port of at least a micropump arranged in the most downstream row is directly connected to an integrated discharge port. The pump unit further includes: a discharge direct-connection mechanism for connecting respective discharge ports of a plurality of micropumps in a middle row directly to the integrated discharge port; an intake direct-connection mechanism for connecting respective intake ports of the micropumps directly to a fluid to be supplied first; a series-connection mechanism for connecting a discharge port of a micropump in an upstream row directly to an intake port of a micropump in a downstream row; and a controller for controlling the discharge direct-connection mechanism, the intake direct-connection mechanism, and the series-connection mechanism.
Abstract:
When discretizing an analysis target part into plural elements and performing analysis, sheet thickness reduction rate or maximum principal strain at an equivalent position including a same element is compared by either a manner of combining two adjacent elements after the analysis or a manner of changing an element discretization size with two types and performing the analysis, and the element where the difference is large is extracted as a fracture risk portion.With this structure, a fracture risk portion can be extracted reliably when a fracture is predicted by a finite element method.
Abstract:
A charged particle beam apparatus comprising a preparatory evacuation chamber (15 in FIG. 1A) into which a sample (12) is conveyed and which is preliminarily evacuated, an ultraviolet irradiation unit (21) which is disposed in the preparatory evacuation chamber (15) and which irradiates the surface of the sample (12) conveyed into the preparatory evacuation chamber (15), with ultraviolet rays for a predetermined time period, and a sample chamber (16) into which the sample (12) is conveyed in the preliminarily evacuated state of the preparatory evacuation chamber (15) or from which the sample (12) is conveyed into the preparatory evacuation chamber (15), wherein the ultraviolet irradiation of the sample (12) by the ultraviolet irradiation unit (21) is performed before the conveyance of the sample (12) into the sample chamber (16), or/and after the conveyance thereof from the sample chamber (16), thereby to remove contamination on the surface of the sample (12).
Abstract:
In an optical communication system, a transmitted signal is modulated with a subcarrier signal having a frequency higher than the frequency of said transmitted signal on the transmission side, the modulated signal light emitted to a transmission channel. On the reception side, the received signal is filtered and decoded by means of a band-pass filter having a center frequency approximately equal to the frequency of the subcarrier signal of the received signal. The above arrangement makes it possible to achieve an arrangement free from the influence of deterioration in the degree of modulation due to spontaneous emission generated from an optical amplifier disposed midway along the transmission channel. The optical amplifier may be an optical differential gain amplifier which has the differential-gain optical input/output characteristics of outputting spontaneous emission of low intensity according to a digital signal value "0" and output light of high intensity according to a digital signal value "1". The arrangement enables optical amplification of signal light without the risk of outputting high-level spontaneous emission due to direct current excitation. It is therefore possible to provide received signals of high quality by eliminating any deterioration in S/N ratio and any deterioration of the degree of modulation of signal light due to spontaneous emission from the optical amplifier disposed midway along the transmission channel.
Abstract:
In a composite data processing system including a plurality of data processing units each containing one or a plurality of instruction processors and a main storage accessed by the instruction processor, and an extended storage shared by the data processing units and accessed by each of the instruction processors, the present invention provides a composite data processing system characterized by including a means for referring to a designated area on the extended storage by each of the instruction processors, a means for rewriting the area described above in accordance with the value of part of the entire part of the area based on the result of a referring operation and a means for generating an instruction for executing the operations from the reference operation to the rewrite operation as an inseparable operation.
Abstract:
A 1-(4-aminobenzyl)-2,3-dioxopiperazine derivative represented by the formula: ##STR1## and an acid addition salt thereof have excellent carcinostatic activity but a low toxicity. Therefore, said compounds are useful as medicines and also as intermediates.