High average power solid-state lasers are performance limited by thermally-induced birefringence inhomogeneities which lead to parasitic de-polarization losses. There is a need for an optical component that can compensate for this parasitic de-polarization.
This invention proposes fabrication of a sandwich of two or more (typically 3) magneto-rheologically finished (MRF’d) birefringent plates with purpose designed arbitrary surface contour profiles and eigen-axis orientation. The tailored surface contour profiles are designed to compensate for the observed de-polarization characteristics of a particular solid-state laser operating in a particular configuration. This is a different approach from compensation for wavefront distortion which is routinely achieved by surface contouring a non-birefringent material e.g. fused silica.
Current stage of technology development: TRL 4-5
U.S. Patent Application No. 2021/0239893 Polarization Manipulation of Free-Space Electromagnetic Radiation Fields published 8/5/2021
- Ability to arbitrarily control the polarization state of a laser beam over its spatial cross-section
- Ability to fabricate a highly tailored beam polarization state profile corrector
- Ability to convert an arbitrary spatially varying laser beam polarization state into a uniform linear polarization across an entire beam aperture
- Applicable to large aperture plates limited only by the size of available birefringent materials and the MRF machine’s capacity to handle the plate
- Improving performance of high-average power lasers by mitigating parasitic de-polarization losses
- Other applications for polarization control in optical systems and display industries
