A high resolution heterodyne laser interferometer without periodic nonlinearity for linear displacement measurements is described. It uses two spatially separated beams with an offset frequency and an interferometer configuration which has no mixed states to prevent polarization mixing. In this research, a simple interferometer configuration for both retroreflector and plane mirror targets which are both applicable to industrial applications was developed. Experimental results show there is no detectable periodic nonlinearity for both of the retro-reflector interferometer and plane mirror interferometer to the noise level of 20 pm. Additionally, the optical configuration has the benefit of doubling the measurement resolution when compared to its respective traditional counterparts. Because of non-symmetry in the plane mirror interferometer, a differential plane mirror interferometer to reduce the thermal error is also discussed. ©2010 Optical Society of America References and links1. W. T. Estler, "High-accuracy displacement interferometry in air," Appl. Opt. 24(6), 808-815 (1985). 2. H. Bosse, and G. Wilkening, "Developments at PTB in nanometrology for support of the semiconductor industry," Meas. Sci. Technol. 16(11), 2155-2166 (2005). 3. N. Bobroff, "Recent advances in displacement measuring interferometry," Meas. Sci. Technol. 4(9), 907-926 (1993). 4. F. C. Demarest, "High-resolution, high-speed, low data age uncertainty, heterodyne displacement measuring interferometer electronics," Meas. Sci. Technol. 9(7), 1024-1030 (1998). 5. R. C. Quenelle, "Nonlinearity in interferometer measurements," Hewlett Packard J. 34, 10 (1983). 6. W. Hou, and G. Wilkening, "Investigation and compensation of the nonlinearity of heterodyne interferometers," Precis. Eng. 14(2), 91-98 (1992) 3195-3203 (2006). 13. M. Tanaka, T. Yamagami, and K. Nakayama, "Linear interpolation of periodic error in a heterodyne laser interferometer at subnanometer levels (dimension measurement)," IEEE Trans. Instrum. Meas. 38(2), 552-554 (1989). 14. C. M. Wu, J. Lawall, and R. D. Deslattes, "Heterodyne interferometer with subatomic periodic nonlinearity,"Appl. Opt. 38(19), 4089-4094 (1999). 15. J. Lawall, and E. Kessler, "Michelson interferometry with 10 pm accuracy," Rev. Sci. Instrum. 71(7), 2669-2676 (2000). 16. T. L. Schmitz, and J. F. Beckwith, "Acousto-optic displacement-measuring interferometer: a new heterodyne interferometer with Anstrom-level periodic error," J. Mod. Opt. 49(13), 2105-2114 (2002

No abstract

Accurate and traceable length metrology is employed by laser frequency stabilization. This paper describes a laser frequency stabilzation technique as a secondary standard with a fractional frequency stability of 5.2×10 −10 with 2 mW of power, suitable for practical applications. The feedback stabilization is driven by an intrinsic mixed mode signal, caused by nonlinear optical phenomena with adjacent modes. The mixed mode signals are described theoretically and experimentally verified.

No abstract