Abstract
Microring weight banks present novel opportunities for reconfigurable, highperformance analog signal processing in photonics. Controlling microring filter response is a challenge due to fabrication variations and thermal sensitivity. Prior work showed continuous weight control of multiple wavelength-division multiplexed signals in a bank of microrings based on calibration and feedforward control. Other prior work has shown resonance locking based on feedback control by monitoring photoabsorption-induced changes in resistance across in-ring photoconductive heaters. In this work, we demonstrate continuous, multi-channel control of a microring weight bank with an effective 5.1 bits of accuracy on 2Gbps signals. Unlike resonance locking, the approach relies on an estimate of filter transmission versus photo-induced resistance changes. We introduce an estimate still capable of providing 4.2 bits of accuracy without any direct transmission measurements. Furthermore, we present a detailed characterization of this response for different values of carrier wavelength offset and power. Feedback weight control renders tractable the weight control problem in reconfigurable analog photonic networks.
Original language | English (US) |
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Pages (from-to) | 26422-26443 |
Number of pages | 22 |
Journal | Optics Express |
Volume | 26 |
Issue number | 20 |
DOIs | |
State | Published - Oct 1 2018 |
All Science Journal Classification (ASJC) codes
- Atomic and Molecular Physics, and Optics