Abstract: A two-wavelength laser-diode (LD) interferometer has been constructed that is based on a phase-shifting technique with an electronic calibration. The phases are equally shifted in opposite directions to each other on an unbalanced interferometer using two wavelengths changed stepwise by separately varying the currents in dual LDs. A feedback interferometer is described with electronics to calibrate the phase shifts and to lock the interferometer on a phase-shift condition by controlling the bias and modulation currents of both LDs. The experimental result is shown to measure a diffraction grating with a 4.6 $mu@m synthetic wavelength. !13
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