GRATING STRUCTURE FOR DIRECTING NON-POLARIZED LIGHT

摘要

A grating structure (11) having a fused silica base includes alternating ridges (21) and grooves (20). The ridges (21) and grooves (20) form a fused silica to air interface. The ridges (21 ) and grooves (20) are configured such that the grating (22) has a ratio between the effective refractive index difference between s-polarization and p-polarization of 1/3. As such, for non-polarized light with an incident angle (?,n) of between 40° and 90° and a wavelength ?=350-1600nm, the grating (22) directs both s-polarization and p-polarization components of the incident light to the -1st order diffraction mode.