Gold-coated photonic crystal fiber based polarization filter for dual communication windows

摘要

Future optical integrated circuits can be created by overcoming the diffraction limit of light that imposes a lower bound on the size limit of optical devices and plasmonics can meet the desired requirements of producing very compact optical devices. A plasmonic based compact and broadband polarizer, capable of producing single polarized ray concurrently around the two communication windows of 1.31 mu m and 1.55 mu m, based on hexagonal lattice photonic crystal fiber is proposed. The results show that the confinement loss of x- and y-polarized modes are 1014.05 dB/cm and 0.048 dB/cm, respectively, at the wavelength of 1.31 mu m meaning that x-polarized mode is 20812 times lossier than y-polarized mode. Similarly, the achieved loss ratio between two orthogonal polarized modes is 6439 at the wavelength of 1.55 mu m. In addition, the filter can also maintain a broad bandwidth of over 800 nm by keeping crosstalk greater than 20 dB for the device length of 100 mu m. The bandwidth and maximum crosstalk value can be extended by loosing compactness of the device. The simultaneous filtering performance around two communication windows with broad bandwidth and compact in length makes the proposed filter a suitable candidate for optical communication and sensing system.