Abstract: To provide an optical gating system capable of performing single-shot, parallel, and ultrafast gating equal to or less than a subpicosecond, without depending on coherence. The optical gating system converts signal light to spatial characteristic signal light whose intensity distribution has spatial periodicity, and emits the spatial characteristic signal light to a gate region (13) so as to be obliquely incident on the gate region (13). In a closed state in an opening and closing operation of the gate region (13), a closed moiré fringe pattern (graph 11) is created in the gate region (13) by overlaying the spatial characteristic signal light and spatial characteristic closed light acting in a direction in which an intensity of the spatial characteristic signal light is decreased in the gate region (13).

Abstract: A dispersion compensator (10) that compensates dispersion occurring in an optical pulse includes a spatial filter (100) from which a pulsed light having a single peak is emitted as an autocorrelation light when a light having a strong correlation with an optical pulse to be dispersion-compensated is introduced into the spatial filter, and from which a scattered light is emitted as a cross-correlation light when a light having a weak correlation with an optical pulse to be dispersion-compensated is introduced into the spatial filter, wherein the dispersion compensator compensates dispersion occurring in the optical pulse having the strong correlation with the optical pulse to be dispersion-compensated, with the autocorrelation light treated as a dispersion-compensated optical pulse.

Abstract: There is provided a chirp indicator of ultrashort optical pulse in which a target ultrashort optical pulse is introduced into a spatial filter formed of a hologram in which is recorded information of chirp quantity of an ultrashort optical pulse used as a reference. The chirp indicator identifies the chirp quantity of the ultrashort optical pulse by detecting an optical correlation between the target ultrashort optical pulse and the ultrashort optical pulse used as a reference. Here, the ultrashort optical pulse to be detected is detected for each hologram, and depending on intensity of an amplitude of light emitted from each hologram, a composition ratio of chirp quantity corresponding to each hologram is deteremined. Then, based on the determined mixture ratio of the chirp quantity, chirp quantity of the ultrashort optical pulse to be detected is determined.

Abstract: There is provided a chirp indicator of ultrashort optical pulse in which a target ultrashort optical pulse is introduced into a spatial filter formed of a hologram in which is recorded information of chirp quantity of an ultrashort optical pulse used as a reference. The chirp indicator identifies the chirp quantity of the ultrashort optical pulse by detecting an optical correlation between the target ultrashort optical pulse and the ultrashort optical pulse used as a reference. Here, the ultrashort optical pulse to be detected is detected for each hologram, and depending on intensity of an amplitude of light emitted from each hologram, a composition ratio of chirp quantity corresponding to each hologram is deteremined. Then, based on the determined mixture ratio of the chirp quantity, chirp quantity of the ultrashort optical pulse to be detected is determined.

Abstract: A signal light pulse and a reference ultra-short light pulse each having an appropriate spatially lateral width are launched simultaneously into an ultra-high-speed optical memory element from both sides of an optical axis thereof at appropriate angles with respect to the axis. Temporal waveforms of the signal light pulse and reference ultra-short light pulse are projected onto a plane. An interference fringe produced by interference between spatial projection images of two moving light waves corresponding to cross-correlation waveforms of the signal light pulse and reference ultra-short light pulse is retained in the ultra-high-speed optical memory element.

Abstract: A signal light pulse to be converted into a two-dimensional space signal and a reference ultra-short light pulse are directed to a dispersion device, a second-harmonic is generated by introducing a one-dimensional frequency light distribution obtained by a one-dimensional Fourier transform lens, the second-harmonic is then subjected to time-to-space conversion through a one-dimensional Fourier transform lens so as to obtain a light wave distribution, and the light wave distribution is then subjected to filtering by a time-frequency filter provided on a filter plane of a one-dimensional space frequency filtering optical system and is further converted into a two-dimensional space signal corresponding to a time-frequency expanded two-dimensional light distribution which represents a relation between time and frequency of the signal pulse light.

Abstract: A DC commutator motor that is driven by a direct current power source obtained by rectifying an alternating current power source includes a plus-side brush made of material having a high resistivity and a minus-side brush made of material having a low resistivity. A capacitor is inserted in and connected parallel to the direct current power source. The commutator motor makes use of specials tubes having different shapes to avoid an incorrect insertion of one of the specials tubes into the insertion hole designed to receive the other of the specials tubes.

Abstract: In a method for directly converting at an ultra-high speed, a signal light pulse (3, 3′) and a reference ultra-short light pulse (4) each having an appropriate spatially lateral width are launched simultaneously into an ultra-high-speed optical memory element (2) from both sides of an optical axis thereof at appropriate angles with respect to the axis, temporal waveforms of the signal light pulse (3, 3′) and reference ultra-short light pulse (4) are projected onto a plane, an interference fringe (5, 5′) produced by interference between spatial projection images of two moving light waves corresponding to cross-correlation waveforms of the signal light pulse (3, 3′) and reference ultra-short light pulse (4) is retained in the ultra-high-speed optical memory element (2), and a spatial distribution of self-diffracted light (7, 7′) of the reference ultra-short light pulse produced in accordance with the spatial distribution of the retained interference fringe corresponding to the cros

Abstract: A DC commutator motor that is driven by a direct current power source obtained by rectifying an alternating current power source includes a plus-side brush made of material having a high resistivity and a minus-side brush made of material having a low resistivity. A capacitor is inserted in and connected parallel to the direct current power source. The commutator motor makes use of specials tubes having different shapes to avoid an incorrect insertion of one of the specials tubes into the insertion hole designed to receive the other of the specials tubes.

Abstract: A DC commutator motor that is driven by a direct current power source obtained by rectifying an alternating current power source includes a plus-side brush made of material having a high resistivity and a minus-side brush made of material having a low resistivity. A capacitor is inserted in and connected parallel to the direct current power source. The commutator motor makes use of specials tubes having different shapes to avoid an incorrect insertion of one of the specials tubes into the insertion hole designed to receive the other of the specials tubes.

Abstract: An electric motor assembly includes a hollow cylindrical casing having a stator disposed inside and adjacent an inner periphery thereof. A rotor is positioned inside the stator and has an output shaft. A bracket made of a thermosetting resin is mounted in one end of the cylindrical casing with a driven member positioned externally of the cylindrical casing and drivingly coupled with the output shaft for rotation about the output shaft. A bearing is mounted externally on the bracket for rotatably supporting the driven member.