Optical Disc Mounts for Lasers

Laser systems require a reliable method of mounting discs or slabs of optical elements in an aerodynamically shaped vane that will be positioned within a high-velocity gas coolant flow. This STFC invention describes an alternative method for mounting an optical disc in a shaped vane for use in cryogenic gas-cooled laser systems.






The mounting methods used in Laser systems must hold the discs sufficiently well to resist potential vibration, minimise interruption of the gas flow and remain firm on cooling to cryogenic temperatures, whilst minimising thermally-induced stress on cooling due to differences in the thermal expansion properties of the disc and chosen vane material. Previous examples have been restricted to operation at or near room temperature. Therefore an alternative mounting method is sought, that will be suited for operation at cryogenic temperatures.


STFC’ s new method is based on edge-clamping of the disc using a spring retainer registered in a shallow groove machined around the edge of the disc. Location in the machined groove ensures the disc is mounted centrally in the vane, which is machined to be the same thickness as the disc. An alignment tolerance between the vane and disc surface of ? 100µm is necessary to ensure minimal disruption to the gas flow between the surfaces of the vane and the disc. The edge-mounting method provides a small, uniform compressive force around the edge of the disc at room temperature, which is sufficiently flexible to accommodate for the difference in contraction between the disc and the vane when the assembly is cooled to cryogenic temperatures. The edge-mounting technique also minimises obscuration of the optical aperture of the disc, which can occur if face mounting techniques are employed.


Three options for the spring retainer are available; ‘C’ Ring, Spring or Bracelets.




  • Laser fusion energy production
  • Laser driven particle acceleration i.e. for proton therapy
  • X-ray and gamma sources
Patent Information:
Country Serial No.
United Kingdom 1410963.1
Germany DE212012000230U
Czech Republic PUV 2014-29803
Korea KR 10-2014-7020406


Optics & Lasers
For Information, Contact:
Elizabeth Bain
IP Manager
STFC Innovations
+44 (0) 1925 60 3680
05.f. Physics