Author:
Zhang Li-Qiong ,Li Yan ,Zhu Min-Hao ,Zhang Ji-Tao ,
Abstract
In order to realize nanometer-scale absolute distance measurements based on Fabry-Pérot interferometry for long-range displacement measurement of the moving coil in Joule balance, the acousto-optic frequency shifter (AOFS) in double-pass configuration is presented, and a tunable frequency difference in a range of 200 MHz is achieved. The focus length of the lens is determined by analyzing the relationship of the tradeoff between the AOFS modulation bandwidth and its diffraction efficiencies; the beam spot of the first-order diffraction beam is guaranteed by accurately positioning the focused beam according to the distribution of the zero-order diffraction beam spot. The experimental single-pass and double-pass peak diffraction efficiency of the AOFS are 79.54% and 61.41%, respectively; the tunable frequency difference of 440-640 MHz, which is twice the single-pass modulation bandwidth output of 220-320 MHz, is obtained by the beat note between the incident beam and the first-order diffraction beam of the double-pass AOFS, and has a good signal-to-noise ratio. Theoretical analysis shows that a folded Fabry-Pérot cavity length displacement of about 53 mm can be measured through the tunable frequency difference achieved by means of double-pass AOFS.
Publisher
Acta Physica Sinica, Chinese Physical Society and Institute of Physics, Chinese Academy of Sciences
Subject
General Physics and Astronomy
Reference21 articles.
1. Wang X H, Hou J D, Chen X Z, Yang D H, Wang Y Q 2000 Acta Opt. Sin. 20 1441 (in Chinese) [王晓辉, 侯继东, 陈徐宗, 杨东海, 王义遒 2000 光学学报 20 1441]
2. Wang X H, Chen X Z, Hou J D, Yang D H, Wang Y Q 2000 Acta Phys. Sin． 49 85 (in Chinese) [王晓辉, 陈徐宗, 侯继东, 杨东海, 王义遒 2000 物理学报 49 85]
3. Donley E A, Heavner T P, Levi F, Tataw M O, Jefferts S R 2005 Rev. Sci. Instrum. 76 063112
4. Wei D, Chen H X, Xiong D Z, Zhang J 2006 Acta Phys. Sin．55 6342 (in Chinese) [卫栋, 陈海霞, 熊德智, 张靖 2006 物理学报 55 6342]
5. Cornelussen R A, Huussen T N, Spreeuw R J C, van Linden, van den Heuvell H B 2004 Appl. Phys. B 78 19