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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This content will become publicly available on July 22, 2025
Electrically Reconfigurable Phase‐Change Transmissive Metasurface
Programmable and reconfigurable optics hold significant potential for transforming a broad spectrum of applications, spanning space explorations to biomedical imaging, gas sensing, and optical cloaking. The ability to adjust the optical properties of components like filters, lenses, and beam steering devices could result in dramatic reductions in size, weight, and power consumption in future optoelectronic devices. Among the potential candidates for reconfigurable optics, chalcogenide‐based phase change materials (PCMs) offer great promise due to their non‐volatile and analogue switching characteristics. Although PCM have found widespread use in electronic data storage, these memory devices are deeply sub‐micron‐sized. To incorporate phase change materials into free‐space optical components, it is essential to scale them up to beyond several hundreds of microns while maintaining reliable switching characteristics. This study demonstrated a non‐mechanical, non‐volatile transmissive filter based on low‐loss PCMs with a 200 × 200 µm2switching area. The device/metafilter can be consistently switched between low‐ and high‐transmission states using electrical pulses with a switching contrast ratio of 5.5 dB. The device was reversibly switched for 1250 cycles before accelerated degradation took place. The work represents an important step toward realizing free‐space reconfigurable optics based on PCMs.
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- Award ID(s):
- 2132929
- PAR ID:
- 10535047
- Publisher / Repository:
- Wiley
- Date Published:
- Journal Name:
- Advanced Materials
- ISSN:
- 0935-9648
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Reconfigurable or programmable photonic devices are rapidly growing and have become an integral part of many optical systems. The ability to selectively modulate electromagnetic waves through electrical stimuli is crucial in the advancement of a variety of applications from data communication and computing devices to environmental science and space explorations. Chalcogenide‐based phase‐change materials (PCMs) are one of the most promising material candidates for reconfigurable photonics due to their large optical contrast between their different solid‐state structural phases. Although significant efforts have been devoted to accurate simulation of PCM‐based devices, in this paper, three important aspects which have often evaded prior models yet having significant impacts on the thermal and phase transition behavior of these devices are highlighted: the enthalpy of fusion, the heat capacity change upon glass transition, as well as the thermal conductivity of liquid‐phase PCMs. The important topic of switching energy scaling in PCM devices, which also helps explain why the three above‐mentioned effects have long been overlooked in electronic PCM memories but only become important in photonics, is further investigated. These findings offer insight to facilitate accurate modeling of PCM‐based photonic devices and can inform the development of more efficient reconfigurable optics.more » « less
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