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The ever-growing data traffic requires greater transmission bandwidth and better energy efficiency in chip scale interconnects. The emerging transistor-laser-based electronic-photonic processing platform stands out for its high electrical-to-optical efficiency. Because transistor lasers operate best at 980 nm, efficient optical interconnects at this wavelength need to be developed for such energy-efficient computing platforms. Phase change materials (PCMs) are good candidates for achieving non-volatile, reconfigurable, zero-static power optical switching. Having bi-stable states under room temperature, a PCM has its permittivity significantly different between its crystalline and amorphous phases. The authors propose to develop a reconfigurable 1 x 2 optical switch by utilizing low loss GeTe PCM to pave the way for the transistor-laser platform at 980 nm. The non-volatility of the proposed device will open up opportunities for other interesting applications such as non-volatile optical memory and the optical equivalence of the field programmable gate array (FPGA).
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Low-power quasi-continuous hybrid volatile/nonvolatile tuning of ring resonators
Programmable photonic integrated circuits are expected to play an increasingly important role in enabling high-bandwidth optical interconnects and large-scale in-memory computing as needed to support the rise of artificial intelligence and machine learning technology. To that end, chalcogenide-based non-volatile phase-change materials (PCMs) present a promising solution due to zero static power. However, high switching voltage and a small number of operating levels present serious roadblocks to the widespread adoption of PCM-programmable units. Here, we demonstrate an electrically programmable wide bandgap Sb2S3-clad silicon ring resonator using a silicon microheater at a complementary-metal–oxide–semiconductor compatible voltage of <3 V. Our device shows a low switching energy of 35.33 nJ (0.48 mJ) for amorphization (crystallization) and reversible phase transitions with high endurance (>2000 switching events) near 1550 nm. Combining a volatile thermo-optic effect with non-volatile PCMs, we demonstrate 7-bit (127 levels) operation with excellent repeatability and reduced power consumption. Our demonstration of low-voltage and low-energy operation, combined with the hybrid volatile–nonvolatile approach, marks a significant step toward integrating PCM-based programmable units in large-scale optical interconnects.
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- Award ID(s):
- 2329089
- PAR ID:
- 10597925
- Publisher / Repository:
- American Institute of Physics
- Date Published:
- Journal Name:
- APL Photonics
- Volume:
- 10
- Issue:
- 2
- ISSN:
- 2378-0967
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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