Broadband extraordinary optical transmission in a narrow subwavelength gap of infrared wire–grid–polarizers

Wire-gird polarizers (WGPs) have placed central roles in a variety of applications such as imaging system, display, and spectroscopy. In this study, we demonstrate the WGPs, where a metallic film is selectively deposited on a Si nanograting substrate by utilizing oblique angle deposition (OAD), with the capability to reach ~81% transmission efficiency over a broad range of the IR spectrum from 3 μm to 5 μm.