10/28/03

High Efficiency, High Damage Threshold Polarizers for Solid State Lasers

Alpine Research Optics (ARO, Boulder, CO) has introduced a new series of high performance polarizers for use with Nd:YAG and Nd:YVO₄ lasers operating at 1064 nm, 532 nm, 355 nm and 266 nm.  The unique feature of these plate polarizers is that they are designed to operate at 68° angle of incidence.  This enables the production of a coating with a higher extinction ratio (>500:1) and broader spectral bandwidth (approximately 5%) than coatings designed for operation at Brewster’s angle (~56°), while still maintaining a high damage threshold (20 J/cm² for a 10 nsec pulse at 1064 nm).  Broad spectral bandwidth is useful even with single line laser sources because it yields greater temperature/humidity stability, and enables operation in focused beams where the angle of incidence varies across the beam. 

ARO’s polarizers are produced on a standard 28.6 mm x 14.3 mm x 3.2mm fused silica substrate.  The second surface contains a high efficiency antireflection coating.  Polarizers with custom sizes, shapes and performance characteristics over the wavelength range of 266 nm to 1550 nm can be produced upon request.

 The optical performance and mechanical durability of these polarizers make them suitable for use in a wide variety of industrial applications, such as micromachining, marking and microlithography.  Their broad spectral bandwidth also makes them suitable for use with the new generation of Nd:YVO₄ ultrafast lasers.