Low-power high-performance fiber-coupled acousto-optic modulator based on novel chalcogenide glass

Chalcogenide glasses, with their broad infrared transmission window and high acousto-optic figure of merit, represent an ideal medium for low-power high-performance acousto-optic modulators (AOMs), potentially overcoming the diffraction efficiency and power consumption limitations of AOMs based on conventional materials. Ge₂₁Sb₁₈S₆₁ chalcogenide glass, characterized by its wide infrared transparency and high refractive index, was systematically investigated for its thermal, physical, optical, and acoustic properties. Using this glass as acousto-optic medium, a high-performance fiber-coupled AOM was successfully fabricated. Experimental results demonstrated that under a RF driving power of 0.52 W, the modulator achieved a diffraction efficiency of 84%, a rise time of 41 ns, and an extinction ratio as high as 61 dB, exhibiting excellent low-power consumption and high-efficiency characteristics. This study provides crucial technical support for the design and development of novel acousto-optic devices, contributing to advancements in high-speed optical communication and fiber sensing applications.

This study aims to overcome the limitations of conventional AOMs in diffraction efficiency and power consumption by employing novel materials with a high acousto-optic figure of merit as the acousto-optic medium. The goal is to develop high-performance, low-power AOMs to meet the growing needs of energy-efficient and high-performance optical modulation in modern optoelectronic systems.

This study employed a systematic material characterization→device fabrication→performance measurement approach to develop a chalcogenide glass-based AOM. The Ge₂₁Sb₁₈S₆₁ glass was first characterized for its thermal, physical, optical, and acoustic properties to verify its suitability as an acousto-optic medium. A fiber-coupled AOM was then fabricated and its performance was experimentally evaluated.

Experimental results demonstrated that Ge₂₁Sb₁₈S₆₁ chalcogenide glass showed an acousto-optic figure of merit of 200×10^-18 s³/g. Under a RF driving power of 0.52 W, the developed AOM achieved a diffraction efficiency of 84%, a rise time of 41 ns, and an extinction ratio as high as 61 dB. Moreover, it maintains stable performance over a temperature range of -40 to 70℃.

Compared to conventional acousto-optic media, the chalcogenide-glass-based AOM demonstrates remarkable advantages in acousto-optic figure of merit, diffraction efficiency, and power consumption, establishing a novel material platform for developing high-performance acousto-optic devices.