Robust electrothermal switching of optical phase change materials through computer-aided adaptive pulse optimization

TL;DR

This paper introduces a computer-aided adaptive pulse optimization method to enhance the reliability and lifetime of electrothermal optical phase change devices, demonstrating improved endurance through patterning and pulse control.

Contribution

The study presents a novel algorithm for real-time pulse adjustment based on optical monitoring, significantly extending device lifespan beyond 13,000 cycles.

Findings

Patterned PCM structures outperform blanket films in endurance.

Adaptive pulse optimization improves switching stability.

Device lifetime is extended through patterning and real-time control.

Abstract

Electrically tunable optical devices present diverse functionalities for manipulating electromagnetic waves by leveraging elements capable of reversibly switching between different optical states. This adaptability in adjusting their responses to electromagnetic waves after fabrication is crucial for developing more efficient and compact optical systems for a broad range of applications including sensing, imaging, telecommunications, and data storage. Chalcogenide-based phase change materials (PCMs) have shown great promise due to their stable, non-volatile phase transition between amorphous and crystalline states. Nonetheless, optimizing the switching parameters of PCM devices and maintaining their stable operation over thousands of cycles with minimal variation can be challenging. In this paper, we report on the critical role of PCM pattern as well as electrical pulse form in achieving reliable and stable switching, extending the operational lifetime of the device beyond 13,000 switching events. To achieve this, we have developed a computer-aided algorithm that monitors optical changes in the device and adjusts the applied voltage in accordance with the phase transformation process, thereby significantly enhancing the lifetime of these reconfigurable devices. Our findings reveal that patterned PCM structures show significantly higher endurance compared to blanket PCM thin films.