Hamamatsu-photonics K.k.

Hamamatsu Photonics Kabushiki Kaisha

Sionyx, Inc.

Takashi Iida

Yoshihisa Warashina

Yoshihiko Mizushima

Toru Hirohata

Kazutoshi Nakajima

Kenichi Sugimoto

Hirofumi Kan

Terumasa Nagano

Koei Yamamoto

Kazuhisa Yamamura

Akira Sakamoto

Katsumi Shibayama

Takafumi Yokino

Tomofumi Suzuki

Masashi Ito

Helmut Teichmann

Ulrich Starker

Dietmar Hiller

Kei Tabata

Eiji Inuzuka

Tomoko Suzuki

Yasuji Hoshino

Prepared is an ntype semiconductor substratehaving a first principal surfaceand a second principal surfaceopposed to each other, and having a ptype semiconductor regionformed on the first principal surfaceside. At least a region opposed to the ptype semiconductor regionin the second principal surfaceof the ntype semiconductor substrateis irradiated with a pulsed laser beam to form an irregular asperity. After formation of the irregular asperity, an accumulation layerwith an impurity concentration higher than that of the ntype semiconductor substrateis formed on the second principal surfaceside of the ntype semiconductor substrate. After formation of the accumulation layer, the ntype semiconductor substrateis subjected to a thermal treatment.

Semiconductor light-detecting element

Prepared is an ntype semiconductor substratehaving a first principal surfaceand a second principal surfaceopposed to each other, and having a ptype semiconductor regionformed on the first principal surfaceside. At least a region opposed to the ptype semiconductor regionin the second principal surfaceof the ntype semiconductor substrateis irradiated with a pulsed laser beam to form an irregular asperity. After formation of the irregular asperity, an accumulation layerwith an impurity concentration higher than that of the ntype semiconductor substrateis formed on the second principal surfaceside of the n type semiconductor substrate. After formation of the accumulation layer, the ntype semiconductor substrateis subjected to a thermal treatment.

The spectroscopy moduleis provided with a body portionfor transmitting light L, L, a spectroscopic portionfor dispersing light Lmade incident from the front planeof the body portioninto the body portionto reflect the light on the front plane, a light detecting elementhaving a light detecting portionfor detecting the light Ldispersed and reflected by the spectroscopic portionand electrically connected to a wiringformed on the front planeof the body portionby face-down bonding, and an underfill materialfilled in the body portionside of the light detecting elementto transmit the light L, L. The light detecting elementis provided with a light-passing holethrough which the light Ladvancing into the spectroscopic portionpasses, and a light incident openingof the light-passing holeis partially covered by a light transmitting plate

Spectroscopic module

An optical module comprises: a sub-mount, having four photodiodesand two guide groovesdisposed on an optical element mounting surface; a fiber fixing member, having four V-grooves, four concave mirrors, and two guide railsdisposed on an optical fiber fixing surface; and four optical fibers, fixed to the fiber fixing member. With this optical module, the sub-mountand fiber fixing memberare aligned and fixed by the fitting together of the guide groovesand guide rails. A passive alignment type optical module that enables mass production and cost reduction is thus realized.

Optical module

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

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

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.

Growing community of inventors

Shizuoka, Japan

Takashi Iida