Loss-Tolerant Allpass-Based Filter Bank Design Suitable for Integrated Optics

• Main Authors: Yujia Wang, Ryan Aguinaldo, Truong Nguyen
• Format: Article
• Language: English
• Published: IEEE 2014-01-01
• Series: IEEE Photonics Journal
• Subjects: filter bank; allpass filter; waveguide loss; ring resonator
• Online Access: https://ieeexplore.ieee.org/document/6910234/

This paper presents a novel design algorithm for a filter bank structure that is suitable for photonic integrated circuits. The proposed design is entirely based on the principle of loss-exhibiting allpass filtering, which is a behavior naturally observed in a variety of microscale optical components. The setup and mathematical optimization of the system is explored in detail from a signal processing perspective, and an algorithm based on convex and nonlinear optimization techniques is subsequently presented. The algorithm methodologically utilizes the otherwise-undesirable effect of waveguide loss to derive an allpass-based filter bank structure that is amenable to photonic implementation. The proposed structure is ideal for applications in time-stretched analog-to-digital converters, WDM network channelizers, and general optical signal multiplexers.