Investigation on ultra-compact, high contrast ratio 2D-photonic crystal based all optical 4 × 2 encoder

Optical encoder is playing an essential starring role in optical communication and computing applications. This paper presents a new structure for 4 × 2 optical encoder based on two dimensional photonic crystals. The proposed structure consists of silicon rods in background of air using hexagonal lattice. The proposed structure is composed of four input waveguides and two outputs. The band structure is examined by plane wave expansion method and the performance parameters of the 4 × 2 encoder, namely, normalized output power, footprint, contrast ratio, response time and bit rate are analyzed using finite difference time domain method. The proposed encoder is operated at 1550 nm. The low response time, and small footprint have shown that the encoder is exceptionally suitable for high performance optical networks and photonic computational integrated devices.