A high-efficiency, ultrabroadband dielectric internal reflection grating with rhombus-shaped grooves is designed by a rigorous coupled-wave analysis, and an effective method for predicting spectral bandwidths of gratings from their efficiency maps is presented. The grating can be fabricated from a single dielectric material, and its reflection diffraction efficiency of the -1st order can reach more than 0.99. More importantly, an ultrabroadband top-hat diffraction spectrum with efficiency exceeding 0.98 over 170nm wavelength wide is achieved, which makes the gratings suitable for applications associated with broadband illumination, such as ultrashort pulses.
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics