2002
Sinusoidal wavelength-scanning interferometer with double feedback control for real-time measurement of one-dimensional step-profile
ADVANCED MATERIALS AND DEVICES FOR SENSING AND IMAGING
- ,
- ,
- Volume
- 4919
- Number
- First page
- 227
- Last page
- 234
- Language
- English
- Publishing type
- Research paper (international conference proceedings)
- DOI
- 10.1117/12.465819
- Publisher
- SPIE-INT SOC OPTICAL ENGINEERING
An optical path difference (OPD) and the amplitude of sinusoidal wavelength-scanning are controlled with double feedback control system in an interferometer, so that a ruler marking every wavelength and a ruler with scales smaller than a wavelength are generated. These two rulers enable us to measure an OPD longer than a wavelength in real time. A linear CCD image sensor is used to measure one-dimensional step-profiles in real-time. Two different step profiles with a step height of 1 mum and 20 mum, respectively, are measured with the measurement error less than 8 nm. Measuring time for one measuring point is 0.04 s.
- Link information
- ID information
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- DOI : 10.1117/12.465819
- ISSN : 0277-786X
- Web of Science ID : WOS:000179344200036