阅读说明：本技术 一种两维大偏转角声光偏转系统 (Two-dimensional large deflection angle acousto-optic deflection system ) 是由 吴季 王城强 许智宏 李锟影 陈伟 张星 陈秋华 于 2020-06-10 设计创作，主要内容包括：本发明公开了一种两维大偏转角声光偏转系统。本发明描述的宽频声光移频系统,包括声光偏转器(1)(2)。声光偏转器(1)(2)都在相互垂直的两个面上,都设计有换能器。其中换能器a1与换能器b2工作频率不重叠且存在连续衔接,即低频率换能器使用的最高频率为高频换能器工作的最低频率。换能器b1与换能器a2存在同样的关系。(The invention discloses a two-dimensional large deflection angle acousto-optic deflection system. The invention describes a broadband acousto-optic frequency shift system, which comprises an acousto-optic deflector (1) (2). The acousto-optic deflectors (1) and (2) are arranged on two surfaces which are perpendicular to each other, and are provided with transducers. Where transducer a1 does not overlap with transducer b2 operating frequencies and there is continuous splicing, i.e., the highest frequency used by the low frequency transducer is the lowest frequency at which the high frequency transducer operates. Transducer b1 has the same relationship as transducer a 2.)

1. A two-dimensional large-deflection-angle acousto-optic deflection system is characterized in that the two-dimensional acousto-optic deflection system can realize a larger deflection angle compared with a conventional acousto-optic deflection system.

2. The invention describes a two-dimensional large deflection angle acousto-optic deflection system, which comprises an acousto-optic deflector (1) (2).

3. The acousto-optic medium of the acousto-optic deflector (1) (2) according to claim 2 can be an acousto-optic medium such as tellurium oxide, lead molybdate, quartz crystal, etc.

4. The acousto-optic deflector (1) of claim 2 having transducer a1 operating at a frequency that does not overlap and there is a continuous splice of the acousto-optic deflector (2) transducer b2 operating frequencies, i.e. the highest frequency used by the low frequency transducer is the lowest frequency at which the high frequency transducer operates.

5. The acousto-optic deflector (1) of claim 2 having transducer b1 operating at a frequency that does not overlap and that has a continuous splice with the acousto-optic deflector (2) transducer a2 operating frequency, i.e. the highest frequency used by the low frequency transducer is the lowest frequency at which the high frequency transducer operates.

Technical Field

The invention relates to an acousto-optic system, in particular to an acousto-optic deflection system with two dimensions and a large deflection angle.

Background

The acousto-optic effect is a phenomenon that light is diffracted when passing through a medium disturbed by ultrasonic waves, and the phenomenon is a result of interaction between light waves and sound waves in the medium.

The acousto-optic deflector is a device manufactured based on the acousto-optic effect principle, and controls the deflection direction of a light beam through acousto-optic diffraction. Compared with other deflection devices, the acousto-optic deflector does not introduce mechanical motion in the process of realizing light beam deflection, can realize rapid scanning deflection and random deflection, and has the characteristics of high deflection precision, high speed, good stability and the like. However, the acousto-optic deflector has a larger disadvantage of smaller deflection angle compared with other deflectors (such as galvanometers). The deflection angle of the acousto-optic deflector is generally 3-5 mrad, and the galvanometer can reach 700 mrad. Although acousto-optic deflectors are used in some fine machining and scanning imaging fields because of their excellent performance, how to achieve larger bandwidth and deflection angle is still the focus of research of many scientists at present.

The invention aims to design a two-dimensional acousto-optic deflection system, which has a larger deflection angle than that of a conventional acousto-optic deflector, so that the acousto-optic deflection system can be applied to more fields.

Disclosure of Invention

The invention discloses a two-dimensional large deflection angle acousto-optic deflection system.

The invention describes a broadband acousto-optic frequency shift system, which comprises an acousto-optic deflector (1) (2). The acousto-optic deflectors (1) and (2) are arranged on two surfaces which are perpendicular to each other, and are provided with transducers. Where transducer a1 does not overlap with transducer b2 operating frequencies and there is continuous splicing, i.e., the highest frequency used by the low frequency transducer is the lowest frequency at which the high frequency transducer operates. Transducer b1 has the same relationship as transducer a 2.

Since the acousto-optic deflector works to satisfy the bragg equation:

where θ is the bragg angle, λ is the wavelength of the acoustic wave, and Λ is the characteristic length of the acousto-optic medium, therefore, the calculation formula for the deflection angle a can be obtained as follows:

whereinV is the acoustic velocity and f is the acoustic frequency, further we can get:

as can be seen from the above equation, when f is changed, the deflection angle a is also changed. The acousto-optic deflector changes the deflection angle of the light beam by changing f, and the calculation formula of the deflection angle variable quantity a is obtained as follows:

when the invention is applied, larger delta f can be obtained by the bandwidth superposition of the two groups of transducers, so that large deflection angle variation can be obtained.

The invention has the advantages that: the two-dimensional acousto-optic deflection system has compact structure and convenient adjustment, and can obtain a large deflection angle.

Drawings

FIG. 1 is a diagram of a two-dimensional acousto-optic deflection system with large deflection angle.

Detailed Description

The invention will be further described with reference to the following examples with reference to the accompanying drawings.

As shown in FIG. 1, the acousto-optic deflectors (1) and (2) form a complete large-deflection-angle two-dimensional acousto-optic deflection system. Wherein a1, b1 are transducers in two vertical directions of the acousto-optic deflector (1), and a2, b2 are transducers in two vertical directions of the acousto-optic deflector (2). Transducers a1, b2 diffract in the same plane, as do transducers b1, a 2. And the operating frequencies of the transducers a1, b2 do not overlap and there is a continuous succession of frequencies, i.e. the highest frequency used by the low frequency transducer is the lowest frequency used by the high frequency transducer. The same relationship exists for transducers b1, a 2. Suppose the operating frequency of transducer a1 is ω_1~ω₂ω of transducer b2_2~ω₃，ω₁＜ω₂＜ω₃Let us assume that the operating frequency of the transducer b1 is ω_6~ω₇ω of transducer a2_5~ω₆，ω₅＜ω₆＜ω₇。

In the using process of the system, the system needs to obtain the optimal deflection effect by selecting a proper incident angle. When the two-dimensional acousto-optic deflection system works in a small deflection angle state, the transducers a1 and a2 are driven to deflect light beams passing through the acousto-optic deflection system in two dimensions, and the transducers b1 and b2 do not work. When the two-dimensional acousto-optic deflection system works in a large deflection angle state, the transducers a1 and a2 stop working, and meanwhile, the transducers b1 and b2 are driven to realize deflection of laser beams in two-dimensional directions in a larger deflection angle range. By switching the work between the transducers a1 and a2 and b1 and b2, the deflection angles which can be realized by the transducers are respectively two-dimensional directionsAnd

become intoAndthe purpose of increasing the deflection angle of the system is achieved.