Interferometric detection scheme for measuring wavelength shift using a stabilized interferometer with an additional reference wavelength

Abstract A novel interferometric detection scheme for measuring wavelength shift, with applications to optical sensing systems is described. In this scheme, in addition to the source wavelength to be measured, a further reference wavelength is employed to stabilize the optical path difference of the interferometer. This is designed to make the wavelength detection system insensitive to environmental disturbances such as temperature fluctuations and mechanical vibration, and using this scheme a signal-to-noise ratio improvement of ∼ 25 dB has been shown in a demonstration system.