T.G. Van Kessel, H.K. Wickramasinghe
Optics Letters
Absolute optical ranging has been demonstrated by wavelength-multiplexed interferometry with a range resolution of 200 nm, well below the single-wavelength ambiguity. Two current- and temperature-tunable GaAlAs laser diodes (850 nm) provide an equivalent wavelength below 100 μm and a resolution of less than 200 nm. The achievement of such resolution provides the means for combining single- and multiple-wavelength interferometric measurements to achieve unambiguous distance measurement with nanometer resolution. The ranging system is also used to profile unambiguously an integrated circuit structure with a 2.5-μm surface topography. © 1989 Optical Society of America.
T.G. Van Kessel, H.K. Wickramasinghe
Optics Letters
C.C. Williams, H.K. Wickramasinghe
IUS 1985
C.C. Williams, H.K. Wickramasinghe
SPIE OE/LASE 1988
C.C. Williams, W.P. Hough, et al.
Applied Physics Letters