Results in Optics (Feb 2023)
Numerical investigations of 2-D optical free-form couplers for surface connections of photonic integrated circuits
Abstract
Two-dimensional (2-D) connections and couplers play a key role in the design of computational, highly compact integrated circuits and optical communication circuits. 2-D designs allow for very large-scale optical integration (VLSOI) within photonic chips. In this paper, optimized parabolic 2-D couplers are presented for 2-D or surface connection of two parts of a photonic integrated circuit (PIC). Dimensions and structure optimization has been done by Nelder-Mead method through several design parameters, simultaneously. In addition, the light waves propagation is simulated in the optimized designs for different cases via the Finite Element Method (FEM) and the transmittance diagrams are reported for different design cases. Investigation of coupling rate is shown about 90–95 % for coupling at a 90-degree angle for the wavelength range 800–920 nm and about 80–90 % for the light coupling to the other part of optical chip for the same wavelength range. By comparing the light coupling rate in these 2-D designs with the 3-D samples, it has been found that despite the reduction of dimensions, the light coupling performance is still acceptable. Also, the simulation of the design and the results related to the integration of these couplers are given.
