Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

A compact double-pass acousto-optic modulator system



Elizabeth A. Donley, Thomas P. Heavner, F Levi, M O. Tataw, Steven R. Jefferts


A problem that arises when using acousto-optic modulators (AOMs) to scan the laser frequency is the dependence of the beam diffraction angle on the modulation frequency. Alignment problems with AOM-modulated laser beams can be effectively eliminated by using the AOM in the double-pass configuration, in which beam deflections are compensated. On a second pass through the AOM, the beam with its polarization rotated by 90 degrees is deflected back such that it counterpropagates the incident laser beam and it can be separated from the input beam with a polarizing beam splitter. Here we present our design for a compact, stable, double-pass AOM with 75% double-pass diffraction efficiency and a tuning bandwidth of 60 MHz (FWHM) for light transmitted through a single-mode fiber. The overall efficiency of the system defined as the power out of the single-mode fiber divided by the power in to the apparatus is 60%.
Review of Scientific Instruments


acousto-optic modulation, laser cooling


Donley, E. , Heavner, T. , Levi, F. , Tataw, M. and Jefferts, S. (2005), A compact double-pass acousto-optic modulator system, Review of Scientific Instruments, [online], (Accessed February 23, 2024)
Created June 1, 2005, Updated February 17, 2017