Correcting spatial beam deformation

摘要

The invention disclosed here teaches methods and apparatus for altering the temporal and spatial shape of an optical pulse. The methods correct for the spatial beam deformation caused by the intrinsic DC index gradient in a volume holographic chirped reflective grating (VHCRG). The first set of methods involves a mechanical mean of pre-deforming the VHCRG so that the combination of the deflection caused by the DC index gradient is compensated by the mechanical deformation of the VHCRG. The second set of methods involves compensating the angular deflection caused by the DC index gradient by retracing the diffracted beam back onto itself and by re-diffracting from the same VHCRG. Apparatus for temporally stretching, amplifying and temporally compressing light pulses are disclosed that rely on the methods above.

主权项

1. A method for correcting spatial beam deformation comprising:
resting a volume holographic chirped reflective grating on a mount; receiving an optical beam propagated in free space and directed at the volume holographic chirped reflective grating, the optical beam being temporally stretched, the volume holographic chirped reflective grating causing spatial beam deformation of the optical beam; and applying mechanical pressure to the mounted volume holographic chirped reflective grating, the mechanical pressure being applied approximately from a middle of the mount and causing a bending of the volume holographic chirped reflective grating, the bending being in a direction approximately orthogonal to the optical beam and correcting the spatial beam deformation of the optical beam.