LPT-2 Experimental System for Acousto-Optic Effect

Description

Acousto-optic effect experiment is a new generation of physical experiment instrument in Colleges and universities, is used to study the physical process of electric field and light field interaction in basic physics experiments and related professional experiments, and also applies to the experimental research of optical communication and optical information processing. It can be visually displayed by digital double oscilloscope (Optional).

When ultrasound waves travel in a medium, the medium is subject to elastic strain with periodic changes in both time and space, causing a similar periodical change in the refractive index of the medium. As a result, when a ray of light passes through a medium in the presence of ultrasound waves in the medium, it is diffracted by the medium acting as a phase grating. This is the basic theory of acousto-optic effect.

Acousto-optic effect is classified into normal acousto-optic effect and anomalous acousto-optic effect. In an isotropic medium, the plane of polarization of the incident light is not changed by the acousto-optic interaction (called normal acousto-optic effect); in an anisotropic medium, the plane of polarization of the incident light is altered by the acousto-optic interaction (called anomalous acousto-optic effect). Anomalous acousto-optic effect provides the key foundation for the fabrication of advanced acousto-optic deflectors and tunable acousto-optic filters. Unlike normal acousto-optic effect, anomalous acousto-optic effect cannot be explained by Raman-Nath diffraction. However, by using parametric interaction concepts such as momentum matching and mismatching in nonlinear optics, a unified theory of acousto-optic interaction can be established to explain both normal and anomalous acousto-optic effects. The experiments in this system only cover normal acousto-optic effect in isotropic media.

Experiment Examples 

1. Observe Bragg diffraction and measure Bragg diffraction angle

2. Display acousto-optic modulation waveform

3. Observe acousto-optic deflection phenomenon

4. Measure acousto-optic diffraction efficiency and bandwidth

5. Measure the traveling velocity of ultrasound waves in a medium

6. Simulate optical communication using acousto-optic modulation technique

Specifications