摘要
Ultra-compact multifunctional integrated photonic modules have great practical significance to photonic integrated circuits (PICs).However,the design effect and efficiency of the existing mainstream inverse design algorithms are incompetent when designing these modules.We analyze their shortcomings in this task,and propose a new,to our knowledge,inverse design algorithm named polygon search (PS) algorithm to address these problems.We utilize the PS algorithm to design an integrated dual-channel mode-conversion-crossing waveguide module.This module integrates three functions:interconversion between TE_(0) and TE_(1),interconversion between TE_(0) and TE_(2),and channel crossing within only a 4μm×4μm footprint,and its performance is verified by experimental testing.It not only greatly reduces the total footprint of many PICs but also greatly improves their fabricating robustness.Furthermore,we propose a PS-designed mode mixer and a PS-designed bending waveguide,and connect them with the integrated modules to form a four-channel crossing-mode-division-multiplexing system.This system can provide multiple modes on the basis of channel crossing and transmit the output signal in the same direction in parallel within a single output waveguide,which significantly increases the communication bandwidth and decreases the footprint of PICs.At last,we demonstrate the effect and efficiency advantages of the PS algorithm over several mainstream inverse design algorithms by a comprehensive contrast experiment and explain these advantages in theory from several perspectives.
基金
National Key Research and Development Program of China (2022YFF0706005)
National Natural Science Foundation of China (12272407, 60907003,61805278, 62205376, 62275269, 62275271, 62305387)
China Postdoctoral Science Foundation (2018M633704)
Foundation of NUDT (JC13-02-13, ZK17-03-01)
Program for New Century Excellent Talents in University (NCET-12-0142)
Postgraduate Scientific Research Innovation Project of Hunan Province,China (CX20230009)
Natural Science Foundation of Hunan Province (13JJ3001, 2022JJ40552)。