Nippon Telegraph and Telephone Corporation

Sohan Kawamura

Soichi Oka

Yuichi Akage

Masahiro Ueno

Takashi Sakamoto

Tadayuki Imai

Yurina Tanaka

An optical deflector has a dielectric of a paraelectric phase and deflects light transmitted through the dielectric by applying a voltage in a direction perpendicular to a transmission direction of the dielectric, the optical deflector including, in order, a first temperature control element, a first conductor on which a first sensor is disposed, the dielectric, a second conductor on which a second sensor is disposed, and a second temperature control element, wherein a voltage is applied between the first conductor and the second conductor, the dielectric is irradiated with excitation light having a substantially uniform intensity in an application direction of the voltage, and a temperature of the first conductor and a temperature of the second conductor are set to predetermined temperatures.

Optical deflector and method for determining control condition of optical deflector

An electro-optical device includes an electro-optic crystal, a first electrode, and a second electrode. A voltage is applied to the electro-optic crystal by the first electrode and the second electrode. The electro-optic crystal has an incident surface and an emitting surface parallel to each other and deflects incident light made incident on the incident surface at an acute incident angle in an electric field direction in which a voltage is applied. A rotation axis of an incident angle is parallel to the electric field direction.

Electro-optical device

An angle measurement device according to the present invention relates to an angle measurement device for measuring an incident angle of an incident light ray, and includes: at least one light deflector; a driving power supply; a light receiver; and a calculation unit. The light deflector is of a transmission type, has an electro-optic effect, and is configured to change an optical path of the light ray by a voltage applied from the driving power supply, and cause the light ray to enter the light receiver. The calculation unit is configured to calculate the incident angle based on the voltage at which an intensity of the light ray detected by the light receiver is maximum.

Angle measurement device and method

An optical deflection apparatus is provided with an optical deflection element and a compensating optical element. The optical deflection element deflects incident light in a first direction (a voltage application direction) in which a voltage is applied (one-dimensional scan). The compensating optical element is an element which has an incidence surface and an emission surface, which compensates for a deflection deviation in a second direction that is perpendicular to the first direction and to an optical axis of the incident light of deflected light having been deflected by the optical deflection element and incident from the incidence surface, and which arranges a direction of travel of compensated light to be emitted from the emission surface on a same plane.

Optical deflection device

A laser light scanning apparatus includes: an optical system that generates parallel light from laser light emitted from a light source; an optical deflector that performs one-dimensional deflection on the parallel light from the optical system; and a diffractive optical element that diffracts deflected light from the optical deflector. The diffractive optical element is configured such that the diffracted light is focused along a predetermined axis that extends from the optical deflector toward the diffractive optical element, and the position at which the diffracted light is focused on the predetermined axis changes according to the incidence position of the deflected light.

Laser light scanning device and laser light scanning method

In an embodiment, an optical deflection device includes: an electro-optic crystal comprising KTaNbO, the electro-optic crystal having a first surface and a second surface, the first surface and the second surface facing each other; a first electrode on the first surface of the electro-optic crystal; a second electrode on the second surface of the electro-optic crystal; a power source configured to output a control voltage for forming an electric field inside the electro-optic crystal via the first electrode and the second electrode; and a light source configured to emit a pulse laser to be incident on the electro-optic crystal along an optical axis, the optical axis substantially perpendicular to a direction of the electric field formed by the control voltage, wherein a peak power density of the pulse laser output from the light source at a light incidence surface of the electro-optic crystal is less than 800000 W/cm.

The present invention includes an optical deflector that changes a deflection angle depending on an applied voltage, a voltage control unit that applies a voltage to the optical deflector, and a storage unit that stores a value of a voltage to be output by the voltage control unit. The voltage control unit outputs a voltage of a value stored in the storage unit to the optical deflector. The storage unit stores a goal voltage V=g(t), which provides a deflection angle θ with the goal time dependency θ=θ(t).

Control method of optical deflector, and optical deflection device

On an optical path of a condensing lens (), a varifocal lens () is disposed. The varifocal lens () is formed of an electro-optic crystal such as, e.g., potassium tantalate niobate. A condensation position measurement unit () measures a condensation position where laser light is condensed by the condensing lens (). A condensation position control unit () controls a focal position of the varifocal lens () such that a difference between the condensation position measured by the condensation position measurement unit () and a prescribed condensation position that has been set falls within an acceptable range.

Laser processing device

An optical deflector includes an electro-optical material in a paraelectric phase and having a trap for accumulating charges inside the electro-optical material; an electrode pair formed on facing surfaces of the electro-optical material; a first and second conductor hold units provided so as to hold the electro-optical material and the electrode pair therebetween; a temperature sensor that measures at least one of temperatures of the conductor hold units; and a temperature control unit that controls the temperatures of the conductor hold units, based on the measurement temperature, and the optical deflector sets an optical axis of incident light into the electro-optical material so as to be orthogonal to the electric field direction, applies between the electrode pair an alternating current voltage on which a direct current bias voltage is superimposed, and thereby deflects the incident light, in which the temperatures of the first and second conductor hold units are controlled so as to give the electro-optical material a temperature gradient to make a charge density in the electro-optical material substantially uniform.

Growing community of inventors

Musashino, Japan

Sohan Kawamura