Patent ID: 6256102
Filing Date: 2001-07-03
Classification: G01B

Abstract:
A dual beam low-coherence interferometer with improved signal-to-noise ratio, comprising:means for generating a low coherence light source;means for splitting the light source into at least an outgoing signal and a reference signal;a waveguide for receiving the outgoing signal, the waveguide having a first lens for forming a collimated beam from the outgoing signal onto a target, and the waveguide havinga second lens for forming a focused beam from the outgoing signal onto the target;a reference arm for receiving the reference signal, and having a first means for introducing a first modulated frequency, and a second means for introducing a second modulated frequency; anda detector for detecting a frequency value of the collimated beam and a frequency value of the focused beam from the target, wherein an image of the target can be formed by comparing the frequency value of the collimated beam from the target with the first modulated frequency, and comparing the frequency value of the focused beam from the target with the second modulated frequency without multiscattering signal noise effects.