A tunable subwavelength resonant grating optical filter

A tunable subwavelength resonant grating (SRG) filter with liquid crystal cladding as the tuning layer has been demonstrated for the first time. The filter can be easily fabricated by nanoimprint lithography (NIL). NIL has the advantage of low-cost, high-throughput, and sub-10 nm resolution. The filter has a 17 nm tuning range, which is at least 20 times wider than any previous SRG filter, and 2 nm FWHM. The potential for monolithic integration on a chip, easy fabrication, and low cost will make SRG filter an important element for future WDM optical telecommunication.