Abstract

Ring laser cavities have been widely used in single-frequency laser, ^1-3 mode-locked laser, ⁴ laser gyro, etc. Ring laser cavity can oscillate in either or both of the two counter-propagating directions. Unidirectional operation can be achieved so that the amplitude noise is reduced. Our invention of the reentrant ring laser cavity made it possible to have a compact single-frequency laser suitable for intracavity frequency doubling, ³ In this paper, planar and non-planar multi-reentrant ring cavities are demonstrated. They have the advantage for a mode-locked laser to have a ten-fold reduction in cavity length compared to a conventional linear cavity. They can also be used in trace gas detection for increasing the sensitivity compared to the multi-pass cell technique.

© 2002 Optical Society of America