JPS60247625A - Optical deflector - Google Patents

Optical deflector

Info

Publication number
JPS60247625A
JPS60247625A JP10537884A JP10537884A JPS60247625A JP S60247625 A JPS60247625 A JP S60247625A JP 10537884 A JP10537884 A JP 10537884A JP 10537884 A JP10537884 A JP 10537884A JP S60247625 A JPS60247625 A JP S60247625A
Authority
JP
Japan
Prior art keywords
crystal
light beam
refractive index
elements
vertier
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP10537884A
Other languages
Japanese (ja)
Inventor
Shiro Ogata
司郎 緒方
Junichi Takagi
高木　潤一
Naohisa Inoue
直久 井上
Masaharu Matano
俣野　正治
Maki Yamashita
山下　牧
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Omron Corp
Original Assignee
Tateisi Electronics Co
Omron Tateisi Electronics Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Tateisi Electronics Co, Omron Tateisi Electronics Co filed Critical Tateisi Electronics Co
Priority to JP10537884A priority Critical patent/JPS60247625A/en
Publication of JPS60247625A publication Critical patent/JPS60247625A/en
Pending legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/29—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the position or the direction of light beams, i.e. deflection

Landscapes

  • Physics & Mathematics (AREA)
  • Nonlinear Science (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)

Abstract

PURPOSE:To obtain an exit light beam having a relatively sharp spot by arraying and disposing plural thermal elements for heating or cooling an optical material in the propagation direction of a light beam onto the surface of the optical material of which the refractive index changes with temp. CONSTITUTION:Three Peltier elements 2a-2c are arrayed and provided in the propagating direction (forward and backward direction) of the light beam to the respective top and bottom surfaces of a lithium niobate crystal 1. Temp. gradients are respectively formed vertically in the front, central and rear parts in the crystal 1 when the top surface of the crystal 1 is heated by the upper three Peltier elements and the bottom surface of the crystal 1 is cooled by the lower three Peltier elements 2a-2c. The light beam A is gradually deflected upward by the refractive index gradient formed in the crystal 1 in the process of propagating in the crystal and is emitted from the rear end face of the crystal 1. The diameter of such exit light beam is small and the spot thereof is sharp.

Description

【発明の詳細な説明】 発明の背景 この発明は温度によって屈折率が変化する光学材料を利
用した光偏向器に関する。DETAILED DESCRIPTION OF THE INVENTION BACKGROUND OF THE INVENTION This invention relates to an optical deflector using an optical material whose refractive index changes depending on temperature.

ガラスまたは誘電体などの屈折率は、温度によって変化
することが知られている。このような温度光学効果を生
じさせる光学材料を用いて光を偏向させることが考えら
れる。光学材料の温度を変えるためには、その表面にベ
ルチェ素子やＮｉ−０ｒなどの発熱体を設けることが考
えられる。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 thermo-optical effect. In order to change the temperature of the optical material, it is conceivable to provide a heating element such as a Vertier element or Ni-0r on the surface thereof.

第３図は、光学材料の上下面にベルチェ素子がそれぞれ
設けられた光偏向器の例を示している。温度光学効果を
もつ誘電体結晶、たとえばニオブ酸リチウム（ｌｉＮｂ
ｏａ）の結晶（１）の上下面にベルチェ素子（２）がそ
れぞれ設けられている。ベルチェ素子（２）はよく知ら
れているように１対の伝熱板（３）間に異種の伝導形の
半導体（４）が少なくとも１組設けられ、かつこれらの
半導体（４）が伝熱板（３）に固定された接続導体（図
示路）によってＰ形とＮ形とが交互になるように直列に
接続されているものである。半導体（４）に直流電流を
流すと、１対の伝熱板（３）のうち一方の伝熱板（３）
に熱の発生、他方の伝熱板（３）に熱の吸収が起こる。FIG. 3 shows an example of an optical deflector in which Vertier elements are provided on the upper and lower surfaces of an optical material. Dielectric crystals with thermo-optical effects, such as lithium niobate (liNb)
Vertier elements (2) are provided on the upper and lower surfaces of the crystal (1) of oa), respectively. As is well known, the Bertier 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. The P type and N type are connected in series so as to alternate with each other by connecting conductors (paths shown) fixed to the plate (3). When a direct current is passed through the semiconductor (4), one of the pair of heat exchanger plates (3)
Heat is generated in the heat exchanger plate (3), and heat is absorbed in the other heat exchanger plate (3).

電流の向きを逆にすると、熱の吸収が起こる伝熱板（３
）とが逆になる。伝熱板（３）の外面が発熱吸熱面であ
る。各ベルチェ素子（２）は一方の伝熱板（３）の発熱
吸熱面が結晶（１）の上面または下面に密着した状態で
結晶（１）に固定されている。各ベルチェ素子（２）の
他方の伝熱板（３）の発熱吸熱面には、放熱吸熱フィン
（５）が固定されている。When the direction of the current is reversed, heat absorption occurs on the heat exchanger plate (3
) is reversed. The outer surface of the heat exchanger plate (3) is a heat generating/endothermic surface. Each Vertier element (2) is fixed to the crystal (1) with the heat-generating and endothermic surface of one heat exchanger plate (3) in close contact with the top or bottom surface of the crystal (1). A heat-radiating and heat-absorbing fin (5) is fixed to the heat-generating and heat-absorbing surface of the other heat exchanger plate (3) of each Vertier element (2).

上側のベルチェ素子（２）の結晶（１）側の伝熱板（３
）に発熱を起こさせるように電源（図示路）からこのベ
ルチェ素子（２）に電流を流し、下側のベルチェ素子（
２）の結晶（１）側の伝熱板（３）に吸熱を起こさせる
ように電源（図示路）からこのベルチェ素子（２）に電
流を流すと、結晶（１）の上面が加熱され、下面が冷却
される。これによって結晶（１）内部にその上下方向に
温度勾配が発生し、この温度勾配によって結晶内部に屈
折率の勾配が生じる。Heat transfer plate (3) on the crystal (1) side of the upper Vertier element (2)
), a current is passed from the power supply (path shown) to this Beltier element (2) to generate heat, and the lower Beltier element (
When current is passed from the power supply (path shown) to this Vertier element (2) so as to cause the heat transfer plate (3) on the crystal (1) side of 2) to absorb heat, the top surface of the crystal (1) is heated, The lower surface is cooled. As a result, a temperature gradient is generated inside the crystal (1) in the vertical direction, and this temperature gradient causes a refractive index gradient inside the crystal.

この場合は、結晶（１）内部の上部の屈折率が高くなり
、下部の屈折率が低くなるような屈折率勾配が生じる。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.

結晶（１）の端面から光ビームＡを結晶（１）の上下面
と平行に入射させると、屈折率の勾配によって光ビーム
は上下方向、この場合は上向きに偏向される。偏向され
た出射光ビームを８２で、偏向されていない出射光ビー
ムを８１でそれぞれ示す。光ビームを下向きに偏向する
には、各ベルチェ素子（２）に流す電流の向きを逆にす
ればよい。このような光偏向器では、偏向されて出射さ
れる光ビームのスポットが広がり、ぼやけるという問題
がある。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 at 82 and the output light beam that is not deflected is indicated at 81. In order to deflect the light beam downward, the direction of the current flowing through each Vertier element (2) may be reversed. Such a light deflector has a problem in that the spot of the deflected and emitted light beam spreads and becomes blurred.

発明の概要 この発明は、比較的はっきりとしたスポットをもつ出射
光ビームが得られる光偏向器を提供することを目的とす
る。SUMMARY OF THE INVENTION It is an object of the present invention to provide a light deflector that provides an output light beam with a relatively sharp spot.

この発明による光偏向器は、温度によって屈折率が変化
する光学材料の少なくとも一表面上に、光学材料を加熱
または冷却するための複数の熱素子が光ビームの伝搬方
向に並んで配置されていることを特徴とする。温度光学
効果をもつ光学材料の代表的なものとしては、ガラス、
Ｌｉ　Ｎｂ　０２　、ＰＬＺＴなどがある。光学材料を
加熱または冷却するための熱素子としては、たとえばベ
ルチェ素子、Ｎｉ　−Ｃｒ　１Ｔｉなどの発熱体がある
。In the optical deflector according to the present invention, a plurality of thermal elements for heating or cooling the optical material are arranged in line in the propagation direction of the light beam on at least one surface of the optical material whose refractive index changes depending on the temperature. It is characterized by Typical optical materials with thermo-optical effects include glass,
Examples include Li Nb 02 and PLZT. Examples of the thermal element for heating or cooling the optical material include a Bertier element and a heating element such as Ni-Cr 1Ti.

この発明による光偏向器では、光学材料の少なくとも一
表面上に光学材料を加熱または冷却するための複数の熱
素子が光ビームの伝搬方向に並んで配置されているから
、各熱素子によって光学材料内の光ビーム伝搬方向にお
ける各部に温度勾配を形成することができ、これにより
屈折率勾配を形成することができる。したがって光学材
料に入射された光ビームは、結晶内を伝搬する過程で、
光学材料内の光ビーム伝搬方向における各部に形成され
た屈折率勾配により徐々に偏向されるので、光学材料の
表面上に１個の熱素子が設けられた場合よりも収差が小
さく、比較的はっきりしたスポットをもつ出射光ビーム
が得られる。このことは、たとえば焦点距離の短い厚肉
レンズを用いて結像させた場合よりも、焦点距離の長い
薄肉レンズを複数枚重ね合わせて結像させた方が収差が
少なく像がよりはつきりしていることと同じ理由である
。In the optical deflector according to the present invention, a plurality of thermal elements for heating or cooling the optical material are arranged on at least one surface of the optical material in a line in the propagation direction of the light beam. A temperature gradient can be formed at each part in the optical beam propagation direction within the optical fiber, and thereby a refractive index gradient can be formed. Therefore, the light beam incident on the optical material, in the process of propagating within the crystal,
Since the light beam is gradually deflected by the refractive index gradient formed at each part in the optical material's propagation direction, the aberration is smaller than when a single thermal element is provided on the surface of the optical material, and the light beam is relatively clearly defined. An output light beam having a spot with a sharp angle is obtained. This means that, for example, it is better to form an image by stacking multiple thin lenses with a long focal length than to form an image using a thick lens with a short focal length. It's the same reason I'm doing it.

実施例の説明 第１図は、この発明の第１実施例を示している。この光
偏向器では、ニオブ酸リチウムの結晶（１）の上下面そ
れぞれに、３つのベルチェ素子（２ａ　）　（２ｂ　）
　（２ｃ　）が光ビーム（７）伝搬方向（前後方向）に
並んで設けられている。DESCRIPTION OF THE EMBODIMENTS FIG. 1 shows a first embodiment of the invention. This optical deflector has three Vertier elements (2a) (2b) on each of the upper and lower surfaces of the lithium niobate crystal (1).
(2c) are arranged in line in the propagation direction (back and forth direction) of the light beam (7).

上側の３つのベルチェ素子（２ａ）〜（２Ｃ）によって
結晶（１）の上面を加熱し、下側の３つのベルチェ素子
（２ａ）〜（２Ｃ）によって結晶（１）の下面を冷却す
ると、結晶（１）の上下面の前部、中央部および後部に
設けられたベルチェ素子（２ａ）、（２ｂ）および（２
ｃ）によって結晶（１）内の前部、中央部および後部に
上下方向に温度勾配がそれぞれ形成される。When the upper surface of the crystal (1) is heated by the upper three Vertier elements (2a) to (2C) and the lower surface of the crystal (1) is cooled by the lower three Vertier elements (2a) to (2C), the crystal Vertier elements (2a), (2b) and (2) provided at the front, center and rear of the upper and lower surfaces of (1)
Due to c), temperature gradients are formed vertically in the front, center and rear parts of the crystal (1), respectively.

この温度勾配によって結晶（１）内の前部、中央部およ
び後部に、上部の屈折率が高くなり、下部の屈折率が低
くなるような屈折率勾配が得られる。This temperature gradient creates a refractive index gradient at the front, middle and rear within the crystal (1), with a higher refractive index in the upper part and a lower refractive index in the lower part.

結晶（１）の前端面がら光ビームＡを結晶（１）の上下
面に平行に入射させると、光ビームＡは結晶（１）内を
伝搬する過程で、結晶（１）内の前部、中央部、後部に
形成された屈折率勾配によって、徐々に上向きに偏向さ
れ、Ｂ２で示すように結晶（１）の後端面から出射され
る。この出射光ビームの径は、第３図の光偏向器のよう
に結晶（１）の上下面にベルチェ素子（２）が１個ずつ
設けられた場合における出射光ビームの径より小さくか
つそのスポットがはっきりしている。これは、たとえば
焦点距離の短い厚肉レンズを用いて結像させた場合より
も、焦点距離の長い薄肉レンズを複数枚重ね合わせて結
像させた方が収差が少なく像がよりはっきりしているの
に対応している。When a light beam A is made incident parallel to the upper and lower surfaces of the crystal (1) from the front end surface of the crystal (1), the light beam A propagates through the crystal (1), causing the front end of the crystal (1) to The light is gradually deflected upward by the refractive index gradient formed at the center and rear portion, and is emitted from the rear end face of the crystal (1) as shown by B2. The diameter of this emitted light beam is smaller than the diameter of the emitted light beam when one Vertier element (2) is provided on each of the upper and lower surfaces of the crystal (1) as in the optical deflector shown in FIG. is clear. This means that, for example, when an image is formed using multiple thin lenses with a long focal length, there are fewer aberrations and the image is clearer than when an image is formed using a thick lens with a short focal length. It corresponds to.

また、この光偏向器では、結晶（１）の上面に設けられ
たベルチェ素子（２ａ）〜（２ｃ）と下面に設けられた
ベルチェ素子（２ａ）〜（２Ｃ）の電流の向きを逆にす
ることによって光ビームを下向きに偏向することもでき
る。この場合の出射光ビームをＢ３で示す。In addition, in this optical deflector, the direction of the current in the Bertier elements (2a) to (2c) provided on the upper surface of the crystal (1) and the Bertier elements (2a) to (2C) provided on the lower surface are reversed. This also allows the light beam to be deflected downwards. The emitted light beam in this case is indicated by B3.

さらに、この光偏向器では、結晶（１）の上下面の前部
、中央部および後部に設けられた３組のベルチェ素子（
２ａ　）　（２ｂ　）　（２０＞１７）うち、電流を流
すベルチェ素子の組数を変えることによって偏向角を変
化させることが可能である。結晶（１）の上下面の前部
に設けられたベルチェ素子（２ａ）のみに電流を流した
場合の上向きに偏向された出射光ビームを８２１、結晶
（１）の上下面の後部に設けられたベルチェ素子（２Ｃ
）以外のベルチェ素子（２ａ）（２ｂ）に電流を流した
場合の上向きに偏向された出射光ビームを８２２でそれ
ぞれ示す。Furthermore, in this optical deflector, three sets of Vertier elements (
2a) (2b) (20>17) Among them, it is possible to change the deflection angle by changing the number of pairs of Vertier elements through which current flows. When a current is applied only to the Vertier element (2a) provided at the front of the upper and lower surfaces of the crystal (1), the output light beam 821 is deflected upward. Beltier element (2C
) The output light beams deflected upward when a current is passed through the Vertier elements (2a) and (2b) other than those shown in FIG.

第２図は、この発明の第２実施例を示している。この光
偏向器では、結晶（１）の上面に３つの発熱体（６ａ　
）　（６ｂ　、）　（６ｃ　）　、ｔ；：トエばＮｉ−
Ｃｒが前後方向に所定間隔をおいて設けられている。結
晶（１）の下面には放熱フィン（５）が設けられている
。FIG. 2 shows a second embodiment of the invention. This optical deflector has three heating elements (6a
) (6b,) (6c), t;: Toeba Ni-
Cr are provided at predetermined intervals in the front-rear direction. A radiation fin (5) is provided on the lower surface of the crystal (1).

発熱体（６ａ）〜（６ｃ）に電流が流されると発熱体（
６ａ）〜（６ｃ）が発熱し、結晶（１）の上面の前部、
中央部および後部が加熱される。熱は結晶（１）の上面
から内部に向かって伝導し、結晶（１〉の下面に設けら
れた放熱フィン（５）を介して空気中に放散される。When a current is passed through the heating elements (6a) to (6c), the heating elements (
6a) to (6c) generate heat, and the front part of the upper surface of crystal (1),
The center and rear parts are heated. Heat is conducted from the top surface of the crystal (1) toward the inside and is dissipated into the air via the heat dissipation fins (5) provided on the bottom surface of the crystal (1>).

これによって結晶（１）内の前部、中央部および後部に
上下方向に温度勾配が発生し、この温度勾配によって結
晶（１）内の前部、中央部および後部に屈折率の勾配が
生じる。This generates a temperature gradient in the vertical direction in the front, center, and rear portions of the crystal (1), and this temperature gradient causes a refractive index gradient in the front, center, and rear portions of the crystal (1).

結晶（１）の前端面から光ビームＡを結晶（１）の上下
面に平行に入射させると、光ビームＡは結晶（１）内を
伝搬する過程で、屈折率の勾配によって徐々に上向きに
偏向され、結晶（１）の後端面から８２で示すように出
射される。この光偏向器においても、複数の発熱体（６
ａ）〜（６Ｃ）によって結晶（１）内の前部、中央部お
よび後部に温度勾配（屈折率勾配）が形成されているの
で、第１実施例と同様にスポットのはつきりした出射光
ビームＢ２が得られる。なお、発熱体（６ａ）にのみ電
流を流した場合の出射光ビームを８２１、発熱体（６Ｃ
）以外の２つの発熱体（６ａ　）　＜ｅｂ　）に電流を
流した場合の出射光ビームを８２２で示しておく。When a light beam A is made parallel to the top and bottom surfaces of the crystal (1) from the front end surface of the crystal (1), the light beam A gradually moves upward due to the gradient of the refractive index as it propagates inside the crystal (1). It is deflected and emitted from the rear end face of the crystal (1) as shown at 82. This optical deflector also includes a plurality of heating elements (6
Since a temperature gradient (refractive index gradient) is formed in the front, center and rear parts of the crystal (1) by a) to (6C), the emitted light has a sharp spot as in the first embodiment. A beam B2 is obtained. Note that the output light beam when a current is passed only through the heating element (6a) is 821, and the heating element (6C
822 indicates the emitted light beam when current is passed through two heating elements (6a) <eb) other than ).

上記第１実施例においてはベルチェ素子が結晶の上下面
に設けられているが、結晶の上下面のうち一方の面だけ
に設けてもよい。また結晶の光ビームの伝搬方向に並ん
で配置するベルチェ素子または発熱体の数は２個以上で
あれば任意の数だけ設けることができる。In the first embodiment, the Vertier elements are provided on the upper and lower surfaces of the crystal, but they may be provided on only one of the upper and lower surfaces of the crystal. Further, any number of Vertier elements or heating elements can be provided as long as they are two or more arranged in parallel in the propagation direction of the light beam of the crystal.

【図面の簡単な説明】[Brief explanation of drawings]

第１図はこの発明の第１実施例を示す側面図、第２図は
この発明の第２実施例を示す側面図、第３図は温度光学
誘電体結晶の上下面にベルチェ素子が設けられた光偏向
器を示す側面図である。 （１）・・・温度光学誘電体結晶、（２ａ）〜（２Ｃ，
”）−・・ベルチェ素子、（６ａ）〜（６Ｃ）・・・発
熱体。 以　上 外４名 第１図 第２図 ２FIG. 1 is a side view showing a first embodiment of the invention, FIG. 2 is a side view showing a second embodiment of the invention, and FIG. 3 is a side view showing a second embodiment of the invention. FIG. FIG. 3 is a side view showing an optical deflector. (1)...Thermo-optical dielectric crystal, (2a) to (2C,
”)-...Bertier element, (6a) to (6C)...Heating element. 4 people other than the above Figure 1 Figure 2 Figure 2

Claims (2)

【特許請求の範囲】[Claims] （１）　温度によって屈折率が変化する光学材料の少な
くとも一表面上に、光学材料を加熱または冷却するため
の複数の熱素子が光ビームの伝搬方向に並んで配置され
ている光偏向器。(1) An optical deflector in which a plurality of thermal elements for heating or cooling the optical material are arranged in line in the propagation direction of a light beam on at least one surface of an optical material whose refractive index changes depending on temperature. （２）　熱素子がベルチェ素子であり、複数のベルチェ
素子が光学材料の上下面に光ビームの伝搬方向に並んで
配置されている特許請求の範囲第（１）項記載の光偏向
器。(2) The optical deflector according to claim (1), wherein the thermal element is a Vertier element, and a plurality of Vertier elements are arranged in line in the propagation direction of the light beam on the upper and lower surfaces of the optical material.
JP10537884A 1984-05-23 1984-05-23 Optical deflector Pending JPS60247625A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP10537884A JPS60247625A (en) 1984-05-23 1984-05-23 Optical deflector

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP10537884A JPS60247625A (en) 1984-05-23 1984-05-23 Optical deflector

Publications (1)

Publication Number Publication Date
JPS60247625A true JPS60247625A (en) 1985-12-07

Family

ID=14406015

Family Applications (1)

Application Number Title Priority Date Filing Date
JP10537884A Pending JPS60247625A (en) 1984-05-23 1984-05-23 Optical deflector

Country Status (1)

Country Link
JP (1) JPS60247625A (en)

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