Interpolation of heterodyne interferometric signals based On FPGA

QIU Xiao-qian; LE Yan-fen; WANG Jing

doi:10.3969/j.issn.1001-3806.2011.02.016

In order to measure the phase displacement of a heterodyne interferometer,namely Doppler frequency shift,an interpolation processing method of the heterodyne interferometer based on field programmable gate array(FPGA)was introduced. Based on zero-crossing detection,it starts to interpolate pulses at the rising edges of measurement and reference signals respectively and the phase displacement can be calculated by counting the interpolated pulses.In the experiment,the light source is He-Ne laser with beat frequency of 2.2MHz,measurement device is Michelson's interferometer,and the inserting pulse frequency is 100MHz.The following calculating work,such as counting,multiplication and division,was accomplished by FPGA.From theoretical analysis,the measurement resolution can achieve,(11)/(1000)λ,about 6.9608nm.The result indicates that is of high value for practical application.

Interpolation of heterodyne interferometric signals based On FPGA

1. School of Optical-Electrical and Computer Engineering, Shanghai University of Science and Technology, Shanghai 200093, China

Received Date: 2010-07-07

Accepted Date: 2010-09-06

Available Online: 2011-03-25

Abstract: In order to measure the phase displacement of a heterodyne interferometer,namely Doppler frequency shift,an interpolation processing method of the heterodyne interferometer based on field programmable gate array(FPGA)was introduced. Based on zero-crossing detection,it starts to interpolate pulses at the rising edges of measurement and reference signals respectively and the phase displacement can be calculated by counting the interpolated pulses.In the experiment,the light source is He-Ne laser with beat frequency of 2.2MHz,measurement device is Michelson's interferometer,and the inserting pulse frequency is 100MHz.The following calculating work,such as counting,multiplication and division,was accomplished by FPGA.From theoretical analysis,the measurement resolution can achieve,(11)/(1000)λ,about 6.9608nm.The result indicates that is of high value for practical application.

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Reference (10)

[1]	DAI G L.The study on dual-frequency laser interferometer for nanometrology[D].Beijing:Department of Precision Instruments and Mechanology of Tsinghua University,1998:1-168 (in Chinese).
[2]	CHEN B Y,LID C.Challenges and opportunities of nanomeasurement technology[J].Chinese Journal of Scientific Instrument,2005,26(5):547-550(in Chinese).
[3]	XIE Y,WU Y Z.Zeeman laser interferometer errors for high-precision measurement[J].Applied Optics,1992,31 (7):881-884.
[4]	YANG T B,LUO X,LI D C.Dynamic data collection method of heterodyne interferometer based on FPGA[J].Optical Technigue,2003,29(6):114-116(in Chinese).
[5]	ZHAO Y,LI D C.Heterodyne imederometer signal processing method based on phase and phase integer measurement[J].Acta Metrological Sinica,1995,16(1):31-36(in Chinese).
[6]	ZHANG C M,ZHAO Y,LI D C.Application of filling pulse method to phase detection of uncommon-frequecy signal[J].Opto-electronic Engineering,2000,27(3):40-43(in Chinese).
[7]	OLDHAM N M,KRAMAR J A,HETRICK P S,et al.Electronic limitations in phase meters for heterodyne interferometry[J].Precision Engineering,1993,15 (3):173-179.
[8]	NICOLI J A G.Multipedodical phasemeter:US,4157500[P].1979-06-05.
[9]	MIYAZAKI Ch,AKATSU T,MORI S,et al.A laser measurement system for fast and precise positioning[J].JSME International Journal,1990,33(1):49-54.
[10]	WU Ch M.Heterodyne interferometric system with subnanometer accuracy for measurement of straightness[J].Applied Optics,2004,43(19):3812-3816.

Interpolation of heterodyne interferometric signals based On FPGA

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References

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