摘要
A sinusoidal phase-modulating （SPM） laser diode （LD） interferometer for real-time surface profile measurement is proposed and its principle is analyzed. The phase signal of the surface profile is detected from the sinusoidal phase-modulating interference signal using a real-time phase detection circuit. For 60 × 60 measurement points of the surface profile, the measuring time is 10 ms. A root mean square （RMS） measurement repeatability of 3.93 nm is realized, and the measurement resolution reaches 0.19 nm.
A sinusoidal phase-modulating （SPM） laser diode （LD） interferometer for real-time surface profile measurement is proposed and its principle is analyzed. The phase signal of the surface profile is detected from the sinusoidal phase-modulating interference signal using a real-time phase detection circuit. For 60 × 60 measurement points of the surface profile, the measuring time is 10 ms. A root mean square （RMS） measurement repeatability of 3.93 nm is realized, and the measurement resolution reaches 0.19 nm.
基金
This work was supported by National Natural Science Foundation of China (No. 60578051)
International Cooperation Program of Shanghai Municipal Science & Technology Commission (No. 051107085).
