A broadband optical beam splitter can comprise a non-metallic high contrast grating including a substrate and an array of posts attached to a surface of the substrate. The grating can have a subwavelength period with respect to a preselected optical energy wavelength, the preselected optical energy wavelength within the range of 400 nm to 1.6 μm. Additionally, the broadband optical beam splitter can have a bandwidth of 80 nm to 120 nm and can have an optical energy loss of less than 5%.