Large aperture diffractive elements in PTR glass

摘要

Photo-thermo-refractive (PTR) glasses have shown high efficiency and stability for different applications in laser systems. One of the applications of diffractive elements in PTR glasses is to use them for high power laser beam control and combining which requires an increase of the size of these elements. The opportunities of recording large aperture Bragg gratings by using a translational (multi-frame exposure) technique and by using an Ar~+ ion laser with higher power operating at 334.5 nm and 351 nm are studied. It is shown that photosensitivity of PTR glass at 334.5 nm and 351 nm is comparable to that of 325 nm. Because of higher power at 334.5 nm and 351 nm, the recording of large aperture holograms at these wavelengths is possible. Large-aperture holograms produced by multi-frame technique are demonstrated.