Canon Kabushiki Kaisha

Takahiro Numai

Natsuhiko Mizutani

Jun Nitta

Masakazu Morishita

Koichiro Nakanishi

Yuichi Handa

An electric field is applied to a charge emitting layer. The charge emitting layer absorbs radioactive rays generated by a radiation source, converts the rays into electric charges, and emits the converted charges. The electric field has an intensity satisfying a lower limit of a specification value of a carrier capturing efficiency and an upper limit of a specification value of a dark current density. A dark current at a trap level can be lowered, a carrier capturing efficiency can be improved, and radioactive rays can be detected with small noises and at a high sensitivity. It is possible to reliably detect incident radioactive rays and form an image of incident radioactive rays.

Radiation detector, radiation imaging system, radiation detecting method and radiation imaging method

A semiconductor ring laser gyro comprising two or more ring lasers, the ring lasers being optically independent of each other, is characterized in that a change in beat frequency with respect to a change in angular velocity of a first ring laser is opposite to that of a second ring laser, and angular velocity of rotation of the gyro is detected by a signal representing a difference between a first beat frequency generated by the first ring laser and a second beat frequency generated by the second ring laser.

Ring laser gyro with optically independent semiconductor ring lasers

A gyro comprising a laser device for generating laser beams to be propagated circuitally in opposite directions, wherein an electric signal is taken out from the laser device, the oscillation frequencies of the laser beams being different from each other when the laser device is held stationary.

Laser device having an optical waveguide for discerning movement of an optical gyroscope and an optical gyroscope utilizing same

A semiconductor device having a semiconductor ring laser and a base member with an electrode. The semiconductor ring laser has a circularly formed ridge optical waveguide. A concave region exists at the inside or outside of the waveguide. An electrode layer is provided over the waveguide and concave region, and the electrode and the electrode layer are electrically connected to each other through a conductive member existing in the concave region.

Semiconductor device having a semiconductor ring laser with a circularly formed ridge optical waveguide

A method of producing a semiconductor element is disclosed which comprises a step of preparing a semiconductor element member comprising a projection region on a substrate, a step of embedding an upper surface of the substrate, and upper and side surfaces of the projection region in a potting material, an exposure step of exposing the upper surface of the projection region, a deposition step of depositing an electrode material on the upper surface of the projection region, and a step of removing the potting material.

Method of producing semiconductor element, semiconductor element, and gyroscope

A ring laser of the present invention includes multiple ring resonators with different optical path lengths, wherein at least part of the multiple ring resonators is optically coupled, and a propagating direction of laser light propagating in the ring resonators is not reversed by the coupling.

Ring laser and method for driving a ring laser

To make a time averaged value of a driving current small. After a current I of a first current value not less than an oscillation threshold is injected to a semiconductor laser gyro, a current I of a second current value smaller than the first current value is injected.

Ring laser gyro and driving method therefor with improved driving current

A ring laser gyro wherein a first and a second laser beam propagate with propagating directions different with each other comprises electrode areas on an optical waveguide configuring the ring laser and controls an current injected or a voltage applied to the electrode areas, wherein the oscillating frequencies of the first and second laser beams are different from each other, thereby causing an increase and a decrease in the beat frequency enabling to detect the direction and the speed of a rotation at the same time. With regards to a method for detecting a rotation, the anode of the laser gyro is connected to an operational amplifier. Since the signal outputted from the operational amplifier has a frequency corresponding to the angular speed, it is converted into the voltage by a frequency-voltage conversion circuit so as to detect a rotation. This same method can be used for other types of gyros such as a semiconductor laser gyro, a gas lager gyro and the like.

Control of laser beams in a ring laser gyro

A gyro apparatus has a ring laser in which laser beams of different oscillation frequencies coexist and propagate in mutually opposite circulation directions in an optical resonator, a power source of driving for the ring laser, a device for measuring a difference between the oscillation frequencies of the laser beams, and a device for controlling the power source of driving according to the frequency difference.

Gyro comprising a ring laser in which beams of different oscillation frequencies coexist and propagate in mutually opposite circulation directions, driving method of gyro, and signal detecting method

An optical gyro is provided with a ring laser and detection unit for detecting the beat frequency of said ring laser, and comprises a first ring laser of which beat frequency decreases when the angular velocity increases in a certain direction from a standstill state and a second ring laser of which beat frequency increases when the angular velocity increases regardless of the rotating direction. The first and second ring lasers are so positioned as to be mutually independent optically.

Optical gyro, driving method and signal processing method therefor

A method of manufacturing a semiconductor device comprising the steps of preparing a member having at least one semiconductor layer on a substrate, forming an electrode layer on the semiconductor layer, forming an etching mask on the electrode layer, and forming a mesa profile by etching the electrode layer and the semiconductor layer.

Method of manufacturing semiconductor device and gyro

A gyro comprises a first laser adapted to generate a first laser beam propagating in a single direction as a main mode of operation, and a second laser adapted to generate a second laser beam propagating in a single direction as a main mode of operation. The gyro may have a beat signal detection means and a photodetector for receiving the first and second laser beams. The first laser beam and the second laser beam have different respective oscillation frequencies and interfere with each other.

Gyro apparatus and gyroscope with multiple interfering laser beams affecting an electrical signal flowing therethrough

A semiconductor laser includes a substrate, semiconductor layers formed on the substrate, which construct a cavity including a waveguide with an active region and include at least one semiconductor layer whose refractive-index temperature coefficient is set at a non-positive or minute value sufficient to achieve at least one of the functions of stabilizing an oscillation wavelength of the semiconductor laser and suppressing an overflow of carriers from the active region, and a driving unit for causing electron-hole recombination in the active region.

Temperature-insensitive semiconductor laser

An optical gyro reduces the coupling loss produced when a laser beam is incident upon a photodetector and the noise generated by the laser beam returning to the laser from an external point of reflection. The gyro includes a ring resonator type semiconductor laser for having laser beams transmitted circularly in opposite directions relative to each other. The angle &agr; formed by the surface of the active layer of the semiconductor laser and the lateral surface of each of the low refractive index layers sandwiching the active layer and showing a refractive index lower than the active layer satisfies the requirement of 75&deg;<a<105&deg; over the entire periphery of the low refractive index layer. The gyro detects a beat signal generated in the semiconductor laser.

Gyro and method of operating the same with a modulated frequency signal

A gyro comprises a ring resonator type laser, a vibration table for applying an oscillation to the laser, and a signal processor for processing an output signal from the laser. The signal processor determines the phase angle of the output signal from the amplitude of an oscillation cycle component of the vibration table and that of a higher harmonic component thereof.

Growing community of inventors

Ninomiya-machi, Japan

Takahiro Numai