Abstract: In the first period from pumping start time T1 to time T2 in a laser light source 1, the power of pumping light L1 outputted from a pumping light source 41 so as to irradiate a laser medium 21 is at value P1 whereas the power of light L2 incident on a saturable absorber 30 after being emitted from the laser medium 21 is at an absorption saturation threshold or lower, which causes a resonator 10 to lower its Q-value, thereby suppressing the laser oscillation. Immediately before time T2, the power of light L2 is slightly lower than the absorption saturation threshold. In the second period subsequent to the first period, the power of light L2 is at value P2 greater than the above-mentioned value P1, whereas the power of light L2 exceeds the absorption saturation threshold, which causes the resonator 10 to increase its Q-value, whereby a mirror 12 outputs pulse laser light L3 to the outside.

Abstract: This photocathode comprises: InP substrate 1; InAsx2P1−x2(0<x2<1) buffer layer 2; Inx1Ga1−x1As (1>x1>0.53) light-absorbing layer 3; InAsx3P1−x3 (0<x3<1) electron-emitting layer 4; InAsx3P1−x3 contact layer 5 formed on the electron-emitting layer 4; active layer 8 of an alkali metal or its oxide or fluoride formed on the exposed surface of electron-emitting layer 4; and electrodes 6 and 7.

Abstract: The present passively Q-switched laser comprises a condensing optical system for condensing a laser beam emitted from a laser light source onto the surface of the solid-state laser medium.

Abstract: This semiconductor laser device comprises a semiconductor laser element 10, which is provided with a Cr layer 13 and an Au layer 14, a silicon submount 20, which is provided with a Cr layer 22 and an Au layer 23, and a metal base 30. The surface of the semiconductor laser element 10 on which the Au layer 14 is provided and the surface of the silicon submount 20 on which the Au layer 23 is provided are directly joined together.

Abstract: In the polycrystal diamond thin film in accordance with the present invention, the average particle size is at least 1.5 &mgr;m and, in a Raman spectrum obtained by Raman spectroscopy, a peak intensity near a wave number of 1580 cm−1 has a ratio of 0.2 or less with respect to a peak intensity near a wave number of 1335 cm−1. The photocathode and electron tube in accordance with the present invention comprise the polycrystal diamond thin film as a light-absorbing layer.

Abstract: This photocathode comprises: InP substrate 1; InAsx2P1−x2(0<x2<1) buffer layer 2; Inx1Ga1−x1As (1>x1>0.53) light-absorbing layer 3; InAsx3P1−x3 (0<x3<1) electron-emitting layer 4; InAsx3P1−x3 contact layer 5 formed on the electron-emitting layer 4; active layer 8 of an alkali metal or its oxide or fluoride formed on the exposed surface of electron-emitting layer 4; and electrodes 6 and 7.

Abstract: A semiconductor laser stack apparatus 1 comprises three semiconductor lasers 2a to 2c, two copper plates 3a and 3b, two lead plates 4a and 4b, a supply tube 5, a discharge tube 6, four insulating members 7a to 7d, and three heat sinks 10a to 10c. Here, the heat sink 10a to 10c is formed by a lower planar member 12 formed with a supply water path groove portion 22, an intermediate planar member 14 formed with a plurality of water guiding holes 38, and an upper planar member 16 formed with a discharge water path groove portion 30 which are successively stacked one upon another, whereas their contact surfaces are joined together. The heat sink 10a to 10c is provided with pillar pieces 24 for connecting the bottom face of supply water path groove portion 22 and the lower face of intermediate planar member 14 to each other, and pillar pieces 32 for connecting the bottom face of discharge water path groove portion 30 and the upper face of intermediate planar member 14 to each other.

Abstract: A semiconductor laser stack apparatus 1 comprises three semiconductor lasers 2a to 2c, two copper plates 3a and 3b, two lead plates 4a and 4b, a supply tube 5, a discharge tube 6, four insulating members 7a to 7d, and three heat sinks 10a to 10c. Here, the heat sink 10a to 10c is formed by a lower planar member 12 having an upper face formed with a supply water path groove portion 22, an intermediate planar member 14 formed with a plurality of water guiding holes 38, and an upper planar member 16 having a lower face formed with a discharge water path groove portion 30 which are successively stacked one upon another, whereas their contact surfaces are joined together.

Abstract: This invention relates to a transmission type electron multiplier having a high secondary electron generation efficiency and having the structure capable of detecting positions of incidence of detected light, and also to an electron tube provided therewith. The electron tube comprises a closed container, an electron source, housed in the closed container, for emitting electrons into the closed container, an anode disposed so as to face the electron source, and a transmission type electron multiplier disposed between the electron source and the anode. Particularly, the transmission type electron multiplier comprises a thin film of diamond or a material containing a principal component of diamond, and a reinforcing member for reinforcing the thin film, the reinforcing member having an aperture for exposing a part of the thin film.

Abstract: A photocathode includes a first layer of polycrystalline diamond or a material mainly composed of polycrystalline diamond. The first layer of polycrystalline diamond may be terminated with hydrogen, or oxygen, and a second layer of an alkali metal or compound of an alkali metal, may be provided on the first layer of polycrystalline diamond whose surface is terminated with hydrogen or oxygen. The photocathode can be use for both reflection and transmission electron tubes and can yield a quantum efficiency higher than that in a monocrystal diamond thin film.

Abstract: The present invention relates to an electron tube having a configuration which can maintain its operating stability for a long period of time. The electron tube comprises, at least, a field emitter which is made of diamond or a material mainly composed of diamond and has a surface terminated with hydrogen, and a sealed envelope for accommodating the diamond field emitter. Due to the hydrogen termination, the electron affinity of the diamond field emitter is set to a negative state. Also, hydrogen is enclosed within the sealed envelope. Due to this configuration, the hydrogen-terminated state of the diamond field emitter surface is stabilized, and the electron affinity of the diamond emitter is restrained from changing for a long period of time.

Abstract: A passive eight-pass solid-state laser amplifier is constructed using a quarter-wave plate (11), a total reflection mirror (12), a polarization beam splitter (5), and a total reflection mirror (6) while input/output faces of a hexagonal zigzag slab solid-state laser medium (15) optically pumped are kept nearly perpendicular to pulsed laser light. Thermal birefringence takes place in the laser medium (15) optically pumped with good symmetry by flash lamps or LDs (9) and is compensated for by a quartz 90.degree. rotator (10). Linearly s-polarized laser light reflected by a polarization beam splitter (3) is output as pulsed laser output light (13) to the outside. Owing to this, saturation laser amplification can be achieved using output laser light from a pulsed laser oscillator of relatively low output, as source light.

Abstract: An optical flip-flop circuit which includes an electrical power source for providing an electrical signal, a light-receiving element provided in series with the power source for switching the electrical signal in response to an optical signal, a light-emitting element for emitting the optical signal in response to the electric signal, an electrical signal path between the light-receiving element and the light-emitting element, whereby the electrical signal passes from the power source to the light-emitting element in response to the optical signal received by the light-receiving element, a light path for directing the optical signal from the light-emitting element to the light-receiving element, wherein the light path and the electrical signal path form a signal loop through which a signal circulates, said circulating signal comprising the electrical signal through the electrical signal path portion of the signal loop and the optical signal through the light path portion of the signal loop, and input/output m

Abstract: SUM and CARRY output signals of a first optical half adder are provided to one input terminal of a second optical half adder and an optical latch memory, respectively, and an output signal of the optical latch memory is provided to the other input terminal of the second optical half adder. Input and output of the two optical half adders and optical latch memory are performed through an optical signal. Each optical half adder includes two light-receiving elements each having a symmetrical electrode arrangement in which two Schottky junctions are connected to each other opposite in polarity, and peripheral elements of resistors, a capacitor and an amplifier.

Abstract: A plurality of ultra-high speed light receiving elements are provided each of which has two rectifier junctions being connected to each other opposite in polarity and has a substantially symmetrical electrode arrangement. A bias voltage is applied to each of the light receiving elements from one or a plurality of power sources. Electrical signals produced by the light receiving elements in response to input optical pulse signals are superposed on one another to produce one or a plurality of output electrical signals representing a predetermined logic operation with respect to the input optical pulse signals. Depending on the arrangement of its elements, the optical logic operation system functions as an OR circuit, AND circuit, NOT circuit, EXCLUSIVE OR circuit, or half-adder circuit.

Abstract: An optical memory circuit comprises two photodetectors, and an intermediate signal conductor for connecting the two photodetectors, wherein the two photodetectors and the signal conductor are connected in series in a closed circuit, wherein each of the photodetectors comprises two spaced Schottky electrodes symmetrically disposed on a semiconductor substrate and the signal conductor has a capacitance with a time constant of a potential of the signal conductor such that charges are stored in the signal conductor when an optical write signal is incident on one photodetector and stored charges are released from the signal conductor when an optical read signal is incident on the other photodetector.

Abstract: An apparatus continous imaging apparatus comprising a camera portion and an image receiving portion, Specifically, the image pickup portion comprises an image pickup tube that deflects and scans electron beams and allows electron signals correponding to one pixel or a one-dimensional array of pixels to be converted successively and continuously to time-series light signals. The image receiving portion comprises means that converts to electron beams the time-series light signals transmitted from the pickup tube through at least one optical fiber and which reproduces an image by deflecting the electron beams in synchronism with the camera portion.

Abstract: N type GaAlAs, GaAs and GaAlAs layers are successively grown on a semi-insulating GaAs substrate doped with Cr. Zn is diffused into predetermined portions of those layers to a depth reaching the substrate to form pn junctions between the original n type regions of the layers and their regions are converted to the p from the n type conductivity. The pn junction formed in the GaAs layer serves as a light emitting region.

Abstract: N type Ga.sub.0.7 Al.sub.0.3 As, N type GaAs, N type Ga.sub.0.7 Al.sub.0.3 As and P type Ga.sub.1-0.3 Al.sub.0.3 As are epitaxially grown on an N type GaAs substrate in the named order one after another to form superposed layers. A selected portion of the uppermost layer is etched away along with those portions of the following two layers and one part of the lowermost layer located below the selected uppermost layer portion. P type Ga.sub.1-0.3 Al.sub.0.3 As highly doped with zinc is epitaxially grown to fill the removed portions of the layers. Then the zinc is diffused into the adjacent portions of the layers to form a radiative recombination region of a layer on that portion of the GaAs layer converted to the P type.