Volume‐Phase Holographic Gratings and the Efficiency of Three Simple Volume‐Phase Holographic Gratings

Volume-phase holographic (VPH) gratings show great potential as an alternative dispersing element to the classical surface-relief(SR) gratings presently used in most astronomical spectrographs. We present an introduction to this technology and give the results of an evaluation of three different VPH gratings: a 300 line mm(-1) grating optimized at 1064 nm, a 1200 line mm(-1) grating optimized at 532 nm, and a 2400 line mm(-1) grating optimized for operation at 532 nm.