Multi-Layer Dielectric Grating 524 40 920

High efficiency: typically from 92% to 95% absolute efficiency on TE polarization,
Spectral domain: centred at 1053 nm with ~30 nm bandpass,
Ideal for high energy lasers: Nd:glass (1053-1057 nm),
Groove density: 1740 gr/mm,
Wavefront quality: < λ/3 PV at 1053 nm.
As far as laser induced damage threshold is concerned, gold coated gratings typically present the following values:

400 mJ/cm2 on the grating surface for nanosecond pulses
250 mJ/cm2 on the grating surface for picosecond pulses and lower fluences for shorter pulses or shorter wavelengths.

For many years multi-layer dielectric (MLD) structures composed of alternating high and low index layers have been well known to be highly reflecting. At each interface between a low and high index pair about 4% of the light is reflected. Summing all of the light from the many layers gives an optic that can approach close to complete reflection. Since MLD structures are insulators they lack the conduction electrons that make metals good reflectors and thus can have intrinsically higher damage thresholds.

The manufacture of MLD gratings requires control of the stack of dielectric films, each of a predefined thickness, uniform coating of photoresist and very precise generation of the holographic pattern that defines the groove shape and distribution. The latent image in the photoresist is transferred permanently into the dielectric stack by ion etching.

Ultrafast laser pulse compression and stretching