Dense spectral beam combining with volume Bragg gratings in PTR glass
نویسندگان
چکیده
An incoherent combination of laser radiation from multiple sources into a single near-diffraction-limited beam is an important problem of high power laser design. Energy brightness, but not spectral brightness, can be increased using spectral beam combining (SBC). Initially, SBC was proposed on the basis of conventional surface gratings [1]; however, it was found later that volume Bragg gratings (VBGs) are more efficient for high density SBC with narrow separation between channels [2, 3]. Spectral beam combining by means of VBGs is based on the fact that diffraction efficiency at some wavelength offset from Bragg condition is zero. At this shifted wavelength, the second beam passes the grating without diffraction and is combined with a diffracted beam.
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