2D photonic crystal TM polarizer fabricated by one-step combined nanoimprint and photolithography

Photonic crystal has been widely investigated since it has a great potential to manipulate the flow of light in ultra compact scale. 2D slab photonic crystals for telecommunication wavelengths (e.g., ~1550 nm) have multi-scale structures which are typically micron scale waveguides and deep sub-micron scale air-hole array. Several steps of nanolithography and photolithography are usually used for the fabrication of multi-scale photonic crystals. Such a multi-step lithography process increases fabrication complexity. In this work, we report one-step lithography process to pattern both micron and deep sub-micron features simultaneously using combined-nanoimprint-and-photolithography. As a demonstrator, a 2D silicon photonic crystal transverse magnetic (TM) polarizer was fabricated and characterized.