Slow Light Propagation in Photonic Crystal-Based Meandering Delay Lines Using the PTS Material

Abstract

In this paper, rectangular and triangular photonic crystal (PC) delay lines are designed using PTS (p-toluene sulfonate) at 1550 nm. PTS possesses a high nonlinear refractive index; consequently, when it interacts with an incident light, it provides slow light propagation in a PTS-based device due to the Kerr effect. First, a PC waveguide (PCW) is designed by introducing a line defect made of PTS bars. Such a defect, by using PTS, provides two significant advantages; these include slow group velocity and extremely high optical confinement for a propagating wave through the PCW. Then, two similar PCWs are placed next to each other to investigate the crosstalk phenomenon between them. By choosing an appropriate distance between them, the rectangular and triangular PC reflective meandering delay lines are realized. The rectangular lattice PC reflective meandering delay line exhibits lower propagation losses because this lattice shows a higher transmission coefficient at the corners in comparison with the triangular one. On the other hand, the triangular lattice PC reflective meandering delay line provides very low group velocity for a propagating light wave at the wavelength of 1550 nm; as a consequence, a higher slowing factor is achieved for the triangular lattice PC reflective meandering delay line due to the stronger light–PTS interactions. Simulations are performed using LUMERICAL FDTD SOLUTION v8.15.