Rapid phase shifting fiber interferometer with optical stylus

Optical fiber interferometry holds many advantages for the online measurement of high precision surfaces. Here a fiber interferometer with a wavelength scanning probe is reported. Such an interferometer requires active stabilization against the effects of temperature drift and vibration. A method of multiplexing dual wavelengths into the same fiber, combined with rapid phase shifting and real time phase calculation is investigated. Experimental data show the successful stabilization of the interferometer regardless of environmental perturbation.