Patent ID: 7298428
Filing Date: 2007-11-20
Classification: G01J,G02F,H04B

Abstract:
1. A liquid crystal (LC) optical performance monitor (OPM), comprising: a C-polarizer having a birefringent crystal having a first face and a second face for receiving a collimated beam and separating the collimated beam into a P-polarization beam and a S-polarization beam; a waveplate coupled to the second face of the crystal for rotating the S-polarization beam by 90 degrees, thereby causing the rotated S-polarization beam to have the same polarization as the P-polarization beam; and a liquid crystal tunable filter for receiving and processing the P-polarization beam and the rotated S-polarization beam from the C-polarizer, wherein the P-polarization beam and the rotated S-polarization beam are separate from one another, and beam waists of the P-polarization beam and the rotated S-polarization beam are located substantially on a center of a liquid crystal cavity in the liquid crystal tunable filter.