Fig. 1. Schematic diagram of the all- and mixed-dielectric gratings in the traditional ‘reflectivity bottom + buffer + diffraction top’ combination design strategy.

Fig. 2. The –1st order diffraction efficiency versus the incident angle and line density. The dashed line represents the Littrow angle at 1053 nm with the line density.

Fig. 3. The –1st order diffraction efficiency versus wavelength and line density.

Fig. 4. High-dispersion large-incident-angle dielectric grating with (a)–(d) 1740 l/mm in TE polarization and (e), (f) 1810 l/mm in TM polarization. The fabrication tolerance and EFI tolerance of the (a) duty cycle f versus pillar depth d_G, (b) residual layer thickness d_R versus d_G and (c) base angle β versus f. (d), (e) Diffraction efficiency versus wavelength and incident angle. (f) Normalized EFI distribution.

Fig. 5. Low-dispersion large-deviation-angle dielectric grating. (a) Diffraction efficiency versus incident angle and wavelength in TE polarization. (b) Grating compressor architecture at an incident angle lower than (I), equal to (II) and higher than (III) the Littrow angle. (c) Normalized EFI distribution.

Fig. 6. Trade-off between maximal EFI in the grating pillar and average diffraction efficiency in the working wavelength band for a 1150 l/mm MDG. MDG selection for (a) single TE or TM polarization, and (b) polarization independence.

Fig. 7. Energy scaling factor distribution. The circle represents the design in this paper. The purple circle represents the 1810 l/mm ultra-low EFI design in Section 3. The blue circles denote the 1250 l/mm ultra-broad deviation-angle design in Section 4. The red and orange circles indicate the 1150 l/mm polarization-independent and TE-polarized designs in Section 5, respectively.