Interferometric target detecting apparatus having a light source with more Lorentzian than Gaussian spectral components

摘要

An apparatus for eliminating scattered light from unscattered light (sign in the reflection from a laser-illuminated target and its ambient. The apparatus uses a laser selected for maximum Lorentzian to Gaussian mode content, a stable interferometer having an optical path difference twice the distance to the first zero in the Gaussian pattern of the scattered interferogram, and performs subtraction of the background or scattered interferogram from the unscattered or signal interferogram. The laser is multi-mode and the interferometer is a Fizeau wedge having an optical path difference equal to twice the distance to the first zero in the Gaussian interferogram. The method of making the apparatus is provided.