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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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This content will become publicly available on July 1, 2026
Optical Phase Change Materials
The properties of chalcogenide phase change materials have long attracted the scientific community due to a combination of state retention (i.e., memory) and a large contrast in electrical and optical properties between different solid phases. The last decade has witnessed a vast interest in utilizing this material family for optics and photonics, given their large refractive index modulation, nonvolatility—elusive in optics—and straightforward integration into photonic devices. Thus, designing new optical phase change materials (O-PCMs) and demonstrating high-performance applications have become fast-growing research topics. However, advances in O-PCMs have predominantly followed empirical device developments, driven by their promise in trending technological applications. Nonetheless, a growing interest in revealing their materials science intricacies is driving the much-needed effort toward a holistic understanding and codesign of O-PCMs, which is required to fill knowledge gaps, expand the materials library, and solve the most pressing device performance challenges.
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- PAR ID:
- 10633780
- Publisher / Repository:
- Annual Reviews
- Date Published:
- Journal Name:
- Annual Review of Materials Research
- Volume:
- 55
- Issue:
- 1
- ISSN:
- 1531-7331
- Page Range / eLocation ID:
- 255 to 283
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Abstract Advancements in nanofabrication processes have propelled nonvolatile phase change materials (PCMs) beyond storage‐class applications. They are now making headway in fields such as photonic integrated circuits (PIC), free‐space optics, and plasmonics. This shift is owed to their distinct electrical, optical, and thermal properties between their different atomic structures, which can be reversibly switched through thermal stimuli. However, the reliability of PCM‐based optical components is not yet on par with that of storage‐class devices. This is in part due to the challenges in maintaining a uniform temperature distribution across the PCM volume during phase transformation, which is essential to mitigate stress and element segregation as the device size exceeds a few micrometers. Understanding thermal transport in PCM‐based devices is thus crucial as it dictates not only the durability but also the performance and power consumption of these devices. This article reviews recent advances in the development of PCM‐based photonic devices from a thermal transport perspective and explores potential avenues to enhance device reliability. The aim is to provide insights into how PCM‐based technologies can evolve beyond storage‐class applications, maintain their functionality, and achieve longer lifetimes.more » « less
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