JPH06250136A - Light frequency shifter - Google Patents
Light frequency shifterInfo
- Publication number
- JPH06250136A JPH06250136A JP6277793A JP6277793A JPH06250136A JP H06250136 A JPH06250136 A JP H06250136A JP 6277793 A JP6277793 A JP 6277793A JP 6277793 A JP6277793 A JP 6277793A JP H06250136 A JPH06250136 A JP H06250136A
- Authority
- JP
- Japan
- Prior art keywords
- light
- frequency
- total reflection
- reflection prism
- diffracted light
- 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
Links
Abstract
Description
【０００１】[0001]
【産業上の利用分野】この発明は、光の周波数を変化さ
せるために音響光学素子によるドップラー効果を利用し
た光周波数シフタに関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical frequency shifter that utilizes the Doppler effect of an acousto-optic device to change the frequency of light.
【０００２】[0002]
【従来の技術】従来の光周波数シフタの構成を図２によ
り説明する。１は音響光学素子、２はトランスデュー
サ、３は発振器である。発振器３からの周波数ｆS の信
号によってトランスデューサ２が振動し、音響光学素子
１に超音波振動を伝えると、その進行波に沿って周期的
な屈折率変化が生ずる。これが回折格子として作用する
ため、ブラッグ回折の回折条件を満たす角度で周波数ｆ
O の入射光１１を入れると、回折光１２が発生する。こ
のときドップラ効果による周波数変化が起きる（ドップ
ラーシフトと呼ばれる）。2. Description of the Related Art The structure of a conventional optical frequency shifter will be described with reference to FIG. Reference numeral 1 is an acousto-optic element, 2 is a transducer, and 3 is an oscillator. When the transducer 2 is vibrated by the signal of the frequency f S from the oscillator 3 and ultrasonic vibration is transmitted to the acousto-optic element 1, a periodical refractive index change occurs along the traveling wave. Since this acts as a diffraction grating, the frequency f is set at an angle satisfying the Bragg diffraction condition.
When the incident light 11 of O is introduced, diffracted light 12 is generated. At this time, a frequency change due to the Doppler effect occurs (called Doppler shift).
【０００３】入射光１１に対して回折光１２は超音波進
行波、すなわち、発振器３の周波数だけシフトする。周
波数のシフトする極性は入射光と超音波進行波の相対的
な向きに関係し、図２のように超音波進行波と同一方向
から入射・回折させる場合はマイナス方向にシフトし、
出射光の周波数はｆO −ｆS となる。The diffracted light 12 is shifted by the ultrasonic traveling wave, that is, the frequency of the oscillator 3 with respect to the incident light 11. The polarity of the frequency shift is related to the relative direction of the incident light and the ultrasonic traveling wave, and when incident and diffracted from the same direction as the ultrasonic traveling wave as shown in FIG.
Frequency of the emitted light is f O -f S.
【０００４】[0004]
【発明が解決しようとする課題】入射光に対してできる
だけ大きく周波数のシフトした出射光を得たい場合、図
２の構成によれば、超音波進行波の周波数を高くするし
かない。音響光学素子１の素材を変えたりトランスデュ
ーサ２を薄片化したりで高周波化はできるが、現状では
500ＭＨｚ程度が限界である。In order to obtain outgoing light whose frequency is shifted as much as possible with respect to the incident light, the configuration of FIG. 2 has no choice but to increase the frequency of the ultrasonic traveling wave. Higher frequencies can be achieved by changing the material of the acousto-optic element 1 or thinning the transducer 2, but at present,
The limit is about 500 MHz.
【０００５】この発明は、入射光に対して大きくシフト
した周波数の出射光を取り出すことの出来る光周波数シ
フタを提供することを目的とする。It is an object of the present invention to provide an optical frequency shifter capable of extracting emitted light having a frequency greatly shifted with respect to incident light.
【０００６】[0006]
【課題を解決するための手段】この目的を達成するた
め、この発明の光周波数シフタは、入射光１１を回折し
て回折光１２として出射する音響光学素子１と、回折光
１２を反射する全反射プリズム４とを備え、全反射プリ
ズム４で反射した回折光１２が入射光１１と平行な出射
回折光１３として音響光学素子１から出射されるよう全
反射プリズム４を音響光学素子１に対向配置する。To achieve this object, an optical frequency shifter according to the present invention comprises an acousto-optic device 1 which diffracts an incident light 11 and emits it as a diffracted light 12, and an acousto-optical device 1 which reflects the diffracted light 12. The total reflection prism 4 is provided so as to face the acoustooptic element 1 so that the diffracted light 12 reflected by the total reflection prism 4 is emitted from the acoustooptic element 1 as outgoing diffracted light 13 parallel to the incident light 11. To do.
【０００７】[0007]
【作用】全反射プリズム４への入射光と全反射プリズム
４からの出射光とは平行となり、音響光学素子１への再
入射光は出射光と平行となる。これにより、入射光に対
し出射回折光は発振器の周波数の２倍だけ周波数がシフ
トすることになる。The light incident on the total reflection prism 4 and the light emitted from the total reflection prism 4 are parallel to each other, and the light re-incident on the acoustooptic device 1 is parallel to the light emitted. As a result, the frequency of the emitted diffracted light is shifted by twice the frequency of the oscillator with respect to the incident light.
【０００８】[0008]
【実施例】図１はこの発明に係る光周波数シフタの一実
施例を示す構成図である。1 is a block diagram showing an embodiment of an optical frequency shifter according to the present invention.
【０００９】４は全反射プリズムであり、その他は図２
と同じものである。すなわち、図１は図２に全反射プリ
ズム４を追加したものである。Reference numeral 4 denotes a total reflection prism, and the others are shown in FIG.
Is the same as. That is, FIG. 1 is obtained by adding the total reflection prism 4 to FIG.
【００１０】全反射プリズム４は音響光学素子１に対
し、入射光１１と出射回折光１３とが互いに平行となる
ような位置に対向配置する。The total reflection prism 4 is arranged so as to face the acoustooptic device 1 at a position where the incident light 11 and the outgoing diffracted light 13 are parallel to each other.
【００１１】発振器３からの周波数ｆS の信号によって
トランスデューサ２が振動し、音響光学素子１に超音波
振動を伝えると、その進行波に沿って周期的な屈折率変
化が生じ、これが回折格子として作用するため、ブラッ
グ回折の回折条件を満たす角度で周波数ｆO の入射光を
入れると、回折光１２が発生する。このとき、ドップラ
効果による周波数変化が起きて、出射光の周波数はｆO
−ｆS となる。When the transducer 2 is vibrated by the signal of the frequency f S from the oscillator 3 and ultrasonic vibration is transmitted to the acousto-optic element 1, a periodical refractive index change occurs along the traveling wave, and this acts as a diffraction grating. Therefore, diffracted light 12 is generated when incident light of frequency f O is introduced at an angle satisfying the diffraction condition of Bragg diffraction. At this time, a frequency change due to the Doppler effect occurs and the frequency of the emitted light is f O
-F S.
【００１２】音響光学素子１から出た回折光１２は、全
反射プリズム４へ入射し、反射面で２回反射した後再び
音響光学素子１へ入射する。この際、全反射プリズム４
の特性上、全反射プリズム４への入射光と全反射プリズ
ムからの出射光とは平行になるので、音響光学素子１へ
の再入射光は回折光１２と平行となる。この再入射光は
再び回折を起こすと同時にドップラーシフトを受け、ｆ
O −ｆS −ｆS の周波数で出射回折光１３として音響光
学素子１より出射する。即ち、入射光１１に対して出射
回折光１３は、発振器３の周波数ｆS の２倍だけ周波数
がシフトすることになる。The diffracted light 12 emitted from the acousto-optic element 1 enters the total reflection prism 4, is reflected twice by the reflecting surface, and then enters the acousto-optic element 1 again. At this time, the total reflection prism 4
Since the incident light to the total reflection prism 4 is parallel to the output light from the total reflection prism, the re-incident light to the acousto-optic element 1 is parallel to the diffracted light 12 due to the characteristic. This re-incident light undergoes diffraction again and at the same time undergoes a Doppler shift, f
The emitted diffracted light 13 is emitted from the acoustooptic device 1 at a frequency of O −f S −f S. That is, the frequency of the diffracted light 13 emitted from the incident light 11 is shifted by twice the frequency f S of the oscillator 3.
【００１３】[0013]
【発明の効果】この発明によれば、次の効果がある。The present invention has the following effects.
【００１４】（１）音響光学素子へ加える超音波周波数
の２倍だけ入射光から周波数シフトした出射回折光が得
られる。(1) Emitted diffracted light whose frequency is shifted from the incident light by twice the ultrasonic frequency applied to the acousto-optic device can be obtained.
【００１５】（２）全反射プリズムの入射光と出射光と
が平行になるため、回折が起きる条件で音響光学素子へ
入射光を入射すれば必ず出射回折光が出てくる。(2) Since the incident light and the outgoing light of the total reflection prism are parallel to each other, if the incident light is incident on the acoustooptic device under the condition that diffraction occurs, the outgoing diffracted light always comes out.
【図１】この発明による光周波数シフタの一実施例の構
成図である。FIG. 1 is a configuration diagram of an embodiment of an optical frequency shifter according to the present invention.
【図２】従来の光周波数シフタの構成図である。FIG. 2 is a configuration diagram of a conventional optical frequency shifter.
１ 音響光学素子 ２ トランスデューサ ３ 発振器 ４ 全反射プリズム １１ 入射光 １２ 回折光 １３ 出射回折光 1 Acousto-optic element 2 Transducer 3 Oscillator 4 Total reflection prism 11 Incident light 12 Diffracted light 13 Emitted diffracted light
Claims (1)
出射する音響光学素子(1) と、 回折光(12)を反射する全反射プリズム(4) とを備え、 全反射プリズム(4) で反射した回折光(12)が入射光(11)
と平行な出射回折光(13)として音響光学素子(1) から出
射されるよう全反射プリズム(4) を音響光学素子(1) に
対向配置することを特徴とする光周波数シフタ。1. An acousto-optic device (1) that diffracts incident light (11) and emits it as diffracted light (12), and a total reflection prism (4) that reflects the diffracted light (12). Diffracted light (12) reflected by the prism (4) is incident light (11)
An optical frequency shifter characterized in that a total reflection prism (4) is arranged so as to face the acousto-optic element (1) so as to be emitted from the acousto-optic element (1) as outgoing diffracted light (13) parallel to.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6277793A JPH06250136A (en) | 1993-02-26 | 1993-02-26 | Light frequency shifter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6277793A JPH06250136A (en) | 1993-02-26 | 1993-02-26 | Light frequency shifter |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH06250136A true JPH06250136A (en) | 1994-09-09 |
Family
ID=13210143
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6277793A Pending JPH06250136A (en) | 1993-02-26 | 1993-02-26 | Light frequency shifter |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH06250136A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105425429A (en) * | 2016-01-08 | 2016-03-23 | 中国电子科技集团公司第二十六研究所 | High-extinction-ratio optical-fiber acousto-optic frequency shifter |
-
1993
- 1993-02-26 JP JP6277793A patent/JPH06250136A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105425429A (en) * | 2016-01-08 | 2016-03-23 | 中国电子科技集团公司第二十六研究所 | High-extinction-ratio optical-fiber acousto-optic frequency shifter |
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