Advantages of out-of-plane pulse compression gratings

Diffraction gratings for pulse compression generally perform best at the Littrow angle, but reflection gratings require a nonzero deviation angle to separate the incident and diffracted beams, so they cannot be used at the Littrow angle. In this paper, we show both theoretically and experimentally that most practical multilayer dielectric (MLD) and gold reflection grating designs can be used with quite substantial beam-deviation angles-as large as even 30°-by mounting the grating out-of-plane and choosing the optimal polarization. The impact of polarization when mounting out-of-plane is explained and quantified.