Diffraction gratings with high optical strength for laser resonators

A new approach to the fabrication of efficient diffraction gratings of the reflection type with a high optical strength is proposed. A diffraction grating with an efficiency of 64% was made and used in a resonator of a Q-switched YAG : Nd³⁺ laser. Gratings of this type are capable of withstanding the action of pulsed optical radiation right up to a power density of 180 MW cm^-2. Possible use of such gratings at high angles of incidence of radiation so as to improve the spectral selectivity is considered.