Applications

Applications

Laser Pulse Compression

A 91cm x 42cm MLD grating for laser pulse compression

Gratings for pulse compression have very demading requirements. They must have a 26 to 40 layer multilayer dielectric reflector coating, the devices must operate in a high vacuum, flatness requirements are severe, and laser damage thresholds must be high in the short pulse (0.5 to 10 ps) regime. In these conditions, coating stress must be carefully considered since too much compressive stress will deform the substrate and too much tensile stress will cause coating and substrate crazing.

PGL has developed a low stress coating for silica substrates in cooperation with Osaka University and Okamoto Optics LTD in Yokahama, Japan. High flatness gratings are much easier to produce on silica than other high thermal expansion glasses. The coating process uses ion-assisted deposition to induce the correct amount of film stress to produce a net-zero stress on the device in vacuum. Damage-thresholds of this coating have demonstrated values as high as the best conventional e-beam deposited coatings.

Pulse compressor schematic for the LLE/University of Rochester OMEGA EP

Precision Textured Surfaces

The formation of uniform and repeatable patterns on a nanostructure scale can be produced with the SBIL process. Such patterns on surfaces requiring precise periodic structures of various shapes and geometry can be established directly on substrates as masters and be used to make replicated nanostructered surfaces.Further texturing can be done using ion-etching techniques.

Polarization Control

200 nm Gratings For LCD Display Wire-Grid Polarizers Wire grid polarizers require a fine array of grating lines etched into silica. PGL has produced these structure with periods as small as 200 nm. We are now working on devices that have even smaller periods and methods to apply these patterns to cylindrical substrates for replication.

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