Fused silica fast axis collimator lens for blue high-power laser diodes

摘要

The divergence of laser diodes is asymmetric and must be collimated in the fast-axis and slow-axis to reach an adequatebeam shape for most applications. The most common technical solution is a combination of a Fast Axis Lens (FAC) anda Slow Axis Lens (SAC). These optical components are usually made of glass in combination with an anti-reflectiveoptical coating tuned for a specific wavelength range. During the last decade, high power lasers have become more andmore powerful and the requirements for specific collimation optics continuously increased. The FAC beam shapingperformance is dependent mostly on the lens design and achieved surface quality, while the thermal behavior of the FACis dependent on the laser power and the optical absorption within the lens. The solution for a low absorption lens for ahigh power blue laser diode presented in this paper, is a fused silica FAC. It shows excellent thermal properties andreduces heat generation rate by a factor approximately corresponding to the extinction value ratio when compared toother high refractive glass solutions optimized for blue applications.