Hamamatsu-Photonics K.k.

Hamamatsu Photonics Kabushiki Kaisha

Yoshihiko Mizushima

Toru Hirohata

Yoshihisa Warashina

Takashi Iida

Kenichi Sugimoto

Hirofumi Kan

Kazutoshi Nakajima

Musubu Koishi

Akira Takeshima

Tomoko Suzuki

Yutaka Tsuchiya

Minoru Niigaki

Takeo Sugawara

Kimitsugu Nakamura

Koji Ichie

Masami Yamada

Yasuharu Negi

Koichiro Oba

Tomihiko Kuroyanagi

Toshihiro Suzuki

Toshiyuki Uchiyama

Norio Asakura

Eiji Inuzuka

Tuneo Ihara

Tsuneo Ihara

Kazuji Matsumoto

Chiyoshi Okuyama

Ichizo Ogawa

Morio Takeichi

Minoru Nigaki

Light is made incident into an inhomogeneous medium, and transmitted light or reflected light is detected. The intensity of the detected light is represented by the linear sum of exponential functions of penetration depth using e as a base, or a function formed from the exponents and a function derived from the function. This function includes the physical quantity of the inhomogeneous medium as a coefficient. When light amount measurement data are acquired at a plurality of wavelengths or thicknesses, and the light intensity or other known information is substituted into the function and an expression derived from the function, the physical quantity of the inhomogeneous medium can be determined. Thus, an optical analysis method for an inhomogeneous medium, which is capable of accurate analysis, can be provided.

Optical analysis method for inhomogeneous turbid media

The optical memory device of the present invention comprises a photodetector device which generates a current when light is incident thereon and a light-emitting device which is connected to the photodetector device in series so as to emit light upon receiving a supply of current from the photodetector device and feed back thus emitted light toward the photodetector device.

Optical memory device incorporating photodetector devices and light

Laser light from LD (laser diode) is guided through a fiber to be projected onto a reflector. A receiver detects a return beam of modulated light reflected by the object and outputs a signal reflecting a phase difference between the laser light and the modulation signal. The frequency of the modulation signal is changed based on the signal value so as to finally achieve phase lock. When the phase lock fixes the frequency of the modulation signal, the frequency always corresponds to a distance from LD to the reflector or a group index of a substance filling the optical path. Thus, the distance to the object or the group index of the substance filling the optical path at the time of phase lock can be determined in a simple manner and with a high accuracy, based on the output frequency at the time of phase lock.

Optical measuring apparatus

This invention relates to a semiconductor photo-electron-emitting device for emitting photoelectrons excited from the valence band to the conduction band by incident photons on a semiconductor layer. The device includes a Schottky electrode formed on the emitting surface on a surface of the semiconductor layer, and a conductor layer formed on a surface opposite to the emitting surface. A set bias voltage is applied between the Schottky electrode and the conductor layer to accelerate photoelectrons generated by the excitation of incident photons to the emitting surface and to transfer the accelerated photoelectrons from an energy band of a smaller effective mass to an energy band of a larger effective mass.

Semiconductor photo-electron-emitting device

Photoluminescence or electroluminescence from a material substrate is measured in a photon-counting range. Luminous efficiency of the substrate in its normal operation range is evaluated on the basis of the measured data. The luminescence is measured in an excitation range of the material including a transition excitation level corresponding to a transition luminous level from a low luminous range to a regular, intense luminous range. Two-dimensional distribution of the luminous efficiencies can be obtained by measuring the luminescence from small divided areas of the substrate.

Method and apparatus for evaluating luminous efficiency

A junction, such as a Schottky junction, is formed between a conductive electrode and a semiconductor. A bias voltage is applied between the conductive electrode and an outward-emission-side electrode formed on the semiconductor at the side opposite to the junction. Upon illumination, photoelectrons are internally emitted in the conductive electrode into the semiconductor, transported through the semiconductor, and emitted outward from the semiconductor surface, which has been so treated as to reduce the surface barrier height. The semiconductor is semi-insulating, or a p-n junction is formed therein.

Photoemitter

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 means for providing an input optical signal to the light-receiving element and for emitting a portion of the optical signal directed by the light path.

Optical flip-flop circuit

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. The optical latch memory is an optical flip-flop memory in which a high-speed light-receiving element produces an electric signal in response to an input optical signals, and a high-speed light-emitting element produces, in response to the electric signal guided from the light-receiving element, feed-back light to be applied to the light-receiving element and an output optical signal.

Optical full adder

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.

Optical logic operation system

Times t.sub.1 and t.sub.2 required for two electromagnetic waves having different wavelengths to propagate from a reference point to a target point are measured. Necessary meteorological conditions along the path are also measured to determine refractivities N.sub.1 and N.sub.2 of the path for the two electromagnetic waves as:

Method and apparatus for distance measurement using electromagnetic waves

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.

High speed optical memory circuit

An electromagnetic wave device having an amplification function comprises a medium containing free carriers, means for applying a magnetic field to the medium, means for applying an input electromagnetic wave to the medium in a direction perpendicular to the magnetic field, and means for generating an electric field to accelerating the carriers in the direction of the input electromagnetic wave. A frequency of the input electromagnetic wave is within the range of the plasma frequency plus or minus the cyclotron frequency, and a polarization direction of the input electromagnetic wave is perpendicular both to the magnetic field and its own traveling direction. Furthermore, the device has such functions as oscillation, modulation, frequency conversion, etc. depending on the type of added units.

Electromagnetic wave device

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.

Ultrafast continuous imaging apparatus

In a device for measuring the time interval between first and second optical pulses, the time interval between the first optical pulse and a first one of the train of reference optical clock pulses which is closest to the first optical pulse, and the time interval between the second optical pulse and a second one of the train of reference optical clock pulses which is closest to the second optical pulse are measured, and the time interval between the first and second optical pulses is calculated according to the time intervals thus measured and the time interval between the first and second reference optical clock pulses.

Time interval measuring device

Disclosed are the processes of how to fabricate the microchannel plate for use in electron image intensifying by using a number of glass pipes, each consisting of glass material containing oxides of alkaline earth metals, i.e., magnesium oxide (MgO) or a mixture of magnesium oxide (MgO) and calcium oxide (CaO).

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Shizuoka, Japan

Yoshihiko Mizushima