<title>Fast birefringence measurement using right and left hand circulary polarized laser</title>

Abstract

A fast and accurate birefringence measurement system has been built to study the in-plane birefringence of a rotating optical disk substrate. The fully automated instrument incorporates an axial Zeeman laser which emits both right and left hand circularly polarized lights, stationary polarization elements and a lock-in amplifier. Measurement results showing the accurate and fast features of the system are presented. It is also demonstrated that the in-plane birefringence mapping in rotating substrate of optical disk can be obtained by use of the ability of fast birefringence measurement.

Orthogonal Dual-Frequency SOA-Fiber Laser

“…Because of a wide dynamic range and insensitiveness of the light power variation, optical heterodyne interferometry [1][2][3][4] is of much importance in measurement. In optical heterodyne interferometry an orthogonal dual-frequency laser is needed, but conventional ones such as a He-Ne Zeeman laser [5] have some disadvantages such as low power efficiency and high cost.…”