17 September 1997 Optical heterodyne light source using laser diodes and its application to hybrid measurement
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Proceedings Volume 3098, Optical Inspection and Micromeasurements II; (1997) https://doi.org/10.1117/12.281172
Event: Lasers and Optics in Manufacturing III, 1997, Munich, Germany
Abstract
A novel light source using a laser diode is proposed for the optical heterodyne technique. This light consists of two frequency beams whose polarization directions are orthogonal without special types of laser or frequency modulators. A laser diode is easily modulated in a frequency due to the saw-toothed injection current modulation. In order to compensate the power fluctuation by injection current modulation and to keep the total power constant, a super luminescent diode is added and therefore interference beat signal is sinusoidal. The hybrid interferometer of heterodyne and low coherent measurement is proposed using this novel light source to overcome 2(pi) phase jump. Three dimensional surface profile can be measured with the range from nano to micrometer using this interferometer. This light source is suitable for practical application and can be made in a small unit compared with a Zeeman laser or an acousto-optic modulator.
© (1997) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Yukitoshi Otani, Tadaharu Nakano, Toru Yoshizawa, "Optical heterodyne light source using laser diodes and its application to hybrid measurement", Proc. SPIE 3098, Optical Inspection and Micromeasurements II, (17 September 1997); doi: 10.1117/12.281172; https://doi.org/10.1117/12.281172
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