Vibration insensitive extended range interference microscopy

Using a simultaneous phase sensor, the proposed instrument performs highly repeatable measurements over an extended range in the presence of vibration common to a laboratory setting. Measurement of a 4.5 mu m step standard in the presence of vibration amplitudes of 40 nm produces a repeatability of 1.5nm RMS with vertical scanning data acquired at 400 nm intervals. The outlined method demonstrates the potential to tolerate larger vibration amplitudes up to or beyond a quarter wavelength and to increase the data acquisition step size to that approaching the depth of field of standard microscope imaging systems. (C) 2013 Optical Society of America