JPS60242432A - Optical deflector - Google Patents

Abstract

PURPOSE:To reduce the size and power consumption of the optical deflector by providing semiconductors of different conduction types connected in series so that an N type and a P type alternate and an optical material which varies in refractive index with temperature between a couple of heat conductive plates. CONSTITUTION:A series of semiconductors 4 of different conduction types and dielectric crystal which varies in refractive index with temperature, e.g. crystal 1 of lithium niobate are provided between the couple of ceramic plates 3. The semiconductors 4 are so connected in series that an N type and a P type alternate across a connection conductor. When a power source 5 flows a current to the semiconductors 4, one ceramic plate 3 generates heat according to the direction of the current and the other ceramic plate 3 absorbs the heat to generate a vertical temperature gradient in the crystal 1, thereby obtaining a refractive index gradient. A light beam A when is made incident from an end surface of the crystal 1 in parallel on the ceramic plates 3 is deflected because of the refractive index gradient.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical deflector using an optical material whose refractive index changes depending on humidity.

It is known that the refractive index of glass, dielectric materials, etc. changes depending on temperature. It is conceivable to deflect light using an optical material that produces such a humidity optical effect. In order to obtain a large deflection angle, it is necessary to create a large refractive index gradient inside the optical material, and therefore it is necessary to create a large temperature gradient inside the optical material. In order to obtain such a large temperature gradient,
As shown in Fig. 3, Peltier elements (2) are provided on the upper and lower surfaces of a crystal (1) of an optical material whose refractive index changes depending on temperature, such as lithium niobate (LiNb03), and one Peltier element (2) The top (or bottom) of the crystal (1) is heated, and the other Peltier element (2) is used to heat the crystal (1).
1) Cooling the lower surface (or upper surface) can be considered. As is well known, the Peltier element (2) has at least one set of semiconductors (4) of different types of conductivity placed between a pair of heat exchanger plates (3), and these semiconductors (4) The P-type and N-type are connected in series so as to alternate with each other by connecting conductors (not shown) fixed to the hot plate (3). The shoulder of the heat exchanger plate (3) where direct current is applied to the semiconductor (4) and where heat is generated is opposite to the N side of the heat exchanger plate where heat absorption occurs.

Heat transfer plate (3) on the crystal (1) side of the upper Peltier element (2)
) A current is passed from the power supply (5) to this Peltier element (2) so as to generate heat, and the lower Peltier element (2)
) on the crystal (1) side of the heat exchanger plate (3) When current is passed from the power source (6) to this Peltier element (2) to cause true heat absorption, the upper surface of the crystal (1) is heated and the lower surface is heated. is cooled. This creates a temperature gradient inside the crystal (1) in the vertical direction, and this temperature gradient creates a refractive index gradient inside the crystal (1).In this case, the refractive index at the top inside the crystal (1) A refractive index gradient occurs where the refractive index is high and the lower part is low.The light beam A is directed from the end face of the crystal (1) to the crystal +1
When the light beam is made incident parallel to the upper and lower surfaces of 1, the light beam is deflected in the vertical direction, in this case upward, due to the gradient of the refractive index.

The deflected output beam is designated by B2, and the undeflected output beam is designated by B1. In order to deflect the light beam downward, the direction of the current flowing through each Peltier element (2) may be reversed. In such an optical deflector, a Peltier element (
Since it is necessary to provide 2) on the upper and lower surfaces of the crystal (1), there are problems in that it is difficult to miniaturize and the power consumption increases.

SUMMARY OF THE INVENTION An object of the present invention is to provide an optical deflector that can be downsized and obtain a relatively large deflection angle with little power.

The optical deflector according to the present invention includes at least one set of semiconductors of different types of conductivity between a pair of non-conductive heat exchanger plates, and each semiconductor is connected to an N type and a P type by a connecting conductor fixed to the heat exchanger plate. are alternately connected in series, and an optical material whose refractive index changes depending on the temperature is provided between the pair of heat exchanger plates. Typical optical materials with thermo-optical effects include glass and Ti.
Examples include O2, L i N b O3, and PLZT. When a current is passed through a semiconductor, heat is generated in one of the heat transfer plates,
Heat absorption occurs in the other heat exchanger plate. As a result, the surface of the optical material fixed to one heat exchanger plate is heated, and the surface fixed to the other heat exchanger plate is cooled. This results in the formation of a temperature gradient within the optical material, which results in a refractive index gradient. ``When a light beam is incident on an optical material parallel to the heat exchanger plate, the light beam is deflected by the refractive index gradient.

When Peltier elements are provided on both sides of the optical material, heat generated or absorbed by the heat exchanger plate on the opposite side to the optical material side of the pair of heat exchanger plates of each Peltier element is wasted. The optical deflector according to the present invention can eliminate such wasted heat, and therefore requires less power. Furthermore, since the semiconductor and the optical material are provided between the pair of heat exchanger plates, the optical deflector can be made smaller than when Peltier elements are provided on both sides of the optical material.

Description of examples 1 and 2 show an embodiment of the invention.

Between the pair of upper and lower ceramic plates (3), a plurality of sets of semiconductors (4) of different types of conductivity are provided on both sides thereof, and a dielectric crystal whose refractive index changes depending on humidity, for example, is provided in the left and right center portions. A crystal (1) of lithium niobate is provided.

The semiconductors (4) are connected in series so that N-type and P-type are alternately connected via connection conductors (not shown) fixed to the ceramic plate (3). The upper and lower surfaces of the crystal (1) are closely fixed to the lower surface of the upper ceramic plate (3) and the upper surface of the lower ceramic plate (3) via silicone grease. From the power supply (5) 1. When direct current is passed through the semiconductor (4), heat is generated in one ceramic plate (3) depending on the direction of the current, and heat is absorbed in the other ceramic plate (31m. For example, the upper ceramic plate +3). When Q is caused to generate heat and the lower ceramic plate (3) side absorbs the heat, the upper surface of the crystal (1) is heated and the lower surface is cooled. The state of heat conduction in this case is shown by arrows in FIG. This generates a temperature gradient in the vertical direction inside the crystal (1), and this temperature gradient creates a refractive index gradient inside the crystal (1) with a high refractive index on the upper side and a low refractive index on the lower side. When a light beam A is made parallel to the ceramic plate (3) from the end face of the crystal (1), the light beam is deflected upward due to the gradient of the refractive index. Reverse the direction of the current and insert the upper ceramic plate (31
Let J absorb heat and lower ceramic plate +31
When J is caused to generate heat, the light beam is deflected downward. The undeflected outgoing beam is shown as B1, and the upwardly deflected outgoing beam is shown as B3.

The crystal (1) may be layered in the center between both ceramic plates (3), and the semiconductor (4) may be provided around the crystal (1) between the ceramic plates (3). in this case:
It is necessary to provide the semiconductor (4) so as not to obstruct the incidence and exit of the light beam from the crystal (1).

[Brief explanation of drawings]

1 and 2 show an embodiment of the present invention, FIG. 1 is a front view, FIG. 2 is a perspective view, and FIG. FIG. 7 is a plane view showing the optical deflectors provided with each element force S; (1) - Temperature optical dielectric crystal, (3) - Heat exchanger plate, (4) Fist - Semiconductor. Above, Figure 1, Review of Figure 2, Figure 3, Procedural Amendment (Fube) 1. Indication of the case 1981 Mochiju, J] Application No. 99632
No. 2, Title of the invention Light deflector 3, Relationship to the case of the person making the amendment Patent applicant address 10 Hanazono Tsuchido-cho, Ukyo-ku, Kyoto City Name/designation
(294) Tateishi Electric Co., Ltd. 5, Date of amendment order: Showa 6, Number of inventions increased by the amendment 7, Subject of the amendment: Amendment to the entire specification 1, Name of the invention: Optical deflector 2, Claims (1) At least one set of semiconductors of different types of conductivity is provided between a pair of non-conductive heat exchanger plates, and each semiconductor is connected to an N type and a P type by a connecting conductor fixed to the heat exchanger plate. are connected in series so that they alternate, and between this pair of heat exchanger plates,
An optical deflector equipped with an optical material whose refractive index changes depending on temperature. (2) The optical deflector according to claim 1, wherein the semiconductor is provided on both sides between the heat transfer plates, and the optical material is provided in the center between the heat transfer plates. DETAILED DESCRIPTION BACKGROUND OF THE INVENTION This invention relates to an optical deflector using an optical material whose refractive index changes depending on temperature.It is known that the refractive index of glass or dielectric materials changes depending on temperature. It is conceivable to deflect light using an optical material that produces a thermo-optical effect.In order to obtain a large deflection angle, it is necessary to form a large refractive index gradient inside the optical material, and therefore the optical material It is necessary to form a large temperature gradient inside.In order to obtain such a large temperature gradient,
As shown in Figure 3, optical materials whose refractive index changes depending on temperature, such as lithium niobate (L!, Nb Oa >
A Peltier element (2) is provided on the upper and lower surfaces of the crystal (1), respectively, one Peltier element (2) heats the upper surface (or lower surface) of the crystal (1), and the other Peltier element (2) heats the crystal (1). 1) Cooling the lower surface (or upper surface) can be considered. As is well known, the Peltier element (2) has at least one set of semiconductors (4) of different types of conductivity between a pair of heat exchanger plates (3), and these semiconductors (4) conduct heat transfer. P-type and N-type are connected in series alternately by connecting conductors (paths shown) fixed to the plate (3).When a direct current is passed through the semiconductor (4), one pair Heat is generated in one of the heat exchanger plates (3), and heat is absorbed in the other heat exchanger plate (3).If the direction of the current is reversed, heat generation The heat exchanger plate (3) where heat absorption occurs and the heat exchanger plate (3) where heat absorption occurs are reversed.The heat exchanger plate (3) on the crystal (1) side of the upper Peltier element (2)
), a current is passed from the power supply (5) to this Peltier element (2) so as to generate heat, and the lower Peltier element (2)
When a current is passed from the power source (6) to this Peltier element (2) so as to cause the heat transfer plate (3) on the crystal (1) side to absorb heat, the upper surface of the crystal (1) is heated and the lower surface is cooled. be done. This generates a temperature gradient in the vertical direction inside the crystal (1), and this temperature gradient creates a refractive index gradient inside the crystal (1). In this case, a refractive index gradient occurs in which the refractive index in the upper part of the crystal (1) becomes higher and the refractive index in the lower part becomes lower. When a light beam A is made incident from the end face of the crystal (1) parallel to the upper and lower surfaces of the crystal (1), the light beam is deflected in the vertical direction, in this case upward, due to the gradient of the refractive index. The output light beam that is deflected is indicated by B2, and the output light beam that is not deflected is indicated by 81. In order to deflect the light beam downward, the direction of the current flowing through each Peltier element (2) may be reversed. In such an optical deflector, a Peltier element (2)
Since it is necessary to provide these on the upper and lower surfaces of the crystal (1), there are problems in that it is difficult to miniaturize and the power consumption increases. SUMMARY OF THE INVENTION It is an object of the present invention to provide an optical deflector that can be downsized and provide a relatively large deflection angle with less power. The optical deflector according to the present invention includes at least one set of semiconductors of different types of conductivity between a pair of non-conductive heat exchanger plates, and each semiconductor is connected to an N type and a P type by a connecting conductor fixed to the heat exchanger plate. are alternately connected in series, and an optical material whose refractive index changes depending on the temperature is provided between the pair of heat exchanger plates. Typical optical materials with thermo-optical effects include glass and T.
Examples include i 02 , Lt Nb Os , and PLZT. When no current flows through the semiconductor, heat is generated in one heat exchanger plate, and heat is absorbed in the other heat exchanger plate. As a result, the surface of the optical material fixed to one heat exchanger plate is heated, and the surface fixed to the other heat exchanger plate is cooled. This results in the formation of a temperature gradient within the optical material, which results in a refractive index gradient. When a light beam is incident on an optical material parallel to the heat exchanger plate, the light beam is deflected by the refractive index gradient. When Peltier elements are provided on both sides of the optical material, the heating or cooling thermal energy generated in the heat exchanger plate on the opposite side to the optical material side of the pair of heat exchanger plates for each Peltier element is wasted. . The optical deflector according to the present invention can eliminate such wastage of thermal energy, and therefore requires less electric power. Furthermore, since the semiconductor and the optical material are provided between the pair of heat exchanger plates, the optical deflector can be made smaller than when Peltier elements are provided on both sides of the optical material. DESCRIPTION OF THE EMBODIMENT FIGS. 1 and 2 show an embodiment of the invention. A pair of upper and lower ceramic plates (3) are provided with a plurality of sets of semiconductors (4) of different conduction types on both sides thereof, and a dielectric crystal whose refractive index changes depending on the temperature, for example, in the left and right center portions. A crystal of lithium niobate (1) is provided. Each semiconductor (4) is provided with a ceramic plate (3).
) The N-type and P-type are alternately connected in series through connection conductors (paths shown) fixed to the terminals. Crystal (1
) are closely fixed to the lower surface of the upper ceramic plate (3) and the upper surface of the lower ceramic plate (3) via silicone grease. ? From I[(5), when direct current is passed through the semiconductor (4), heat is generated in one ceramic plate (3) depending on the direction of the current, and heat is absorbed in the other ceramic plate (3). For example, if the upper ceramic plate (3) is made to generate heat and the lower ceramic plate (3) is made to absorb heat, the crystal (
1) The upper surface is heated and the lower surface is cooled. The state of heat conduction in this case is shown by arrows in FIG. This creates a temperature gradient in the vertical direction inside the crystal (1), and this temperature gradient creates a refractive index gradient inside the crystal (1) in which the refractive index in the upper part becomes higher and the refractive index in the lower part becomes lower. . When a light beam A is made parallel to the ceramic plate (3) from the end face of the crystal (1), the light beam is deflected upward due to the gradient of the refractive index. The light beam is deflected downward by reversing the direction of the current, causing the upper ceramic plate (3) to absorb heat and the lower ceramic plate (3) to generate heat. The undeflected output beam is shown at 81, and the upwardly deflected output beam is shown at 83. A crystal (1) is provided in the center between both ceramic plates (3),
The semiconductor (4) is placed between the ceramic plates (3) and the crystal (1)
).In this case,
It is necessary to provide the semiconductor (4) so as not to obstruct the incidence and exit of the light beam into the crystal (1). 4. Brief description of the drawings FIGS. 1 and 2 show an embodiment of the present invention. FIG. 1 is a front view, FIG. 2 is a perspective view, and FIG. 3 is a Peltier device on both upper and lower surfaces of a dielectric crystal. FIG. (1)...Thermo-optical dielectric crystal, (3)...Heat exchange plate, (4)...Semiconductor. 4 people other than the above

Claims (2)

[Claims] (1) At least one set of semiconductors of different types of conductivity is provided between a pair of non-conductive heat exchanger plates, and each semiconductor is alternately N-type and P-type by a connecting conductor fixed to the heat exchanger plate. They are connected in series, and between this pair of heat exchanger plates,
An optical deflector equipped with an optical material whose refractive index changes depending on temperature. (2) The optical deflector according to claim (1), wherein the semiconductor is provided on both sides between the heat exchanger plates, and the optical material is provided at the center between the heat exchanger plates.