Ultra-compact exciton polariton modulator based on van der Waals semiconductors

Seong Won Lee; Jong Seok Lee; Woo Hun Choi; Daegwang Choi; Su-Hyun Gong

doi:10.1038/s41467-024-46701-1

Ultra-compact exciton polariton modulator based on van der Waals semiconductors

Nat Commun. 2024 Mar 14;15(1):2331. doi: 10.1038/s41467-024-46701-1.

Authors

Seong Won Lee^#^{1

2}, Jong Seok Lee^#^{1

2}, Woo Hun Choi^{1

2}, Daegwang Choi^{1

2}, Su-Hyun Gong^{3

4}

Affiliations

¹ Department of Physics, Korea University, Seoul, 02841, South Korea.
² KU Photonics Center, Korea University, Seoul, 02841, South Korea.
³ Department of Physics, Korea University, Seoul, 02841, South Korea. shgong@korea.ac.kr.
⁴ KU Photonics Center, Korea University, Seoul, 02841, South Korea. shgong@korea.ac.kr.

^# Contributed equally.

Abstract

With the rapid emergence of artificial intelligence (AI) technology and the exponential growth in data generation, there is an increasing demand for high-performance and highly integratable optical modulators. In this work, we present an ultra-compact exciton-polariton Mach-Zehnder (MZ) modulator based on WS₂ multilayers. The guided exciton-polariton modes arise in an ultrathin WS₂ waveguide due to the strong excitonic resonance. By locally exciting excitons using a modulation laser in one arm of the MZ modulator, we induce changes in the effective refractive index of the polariton mode, resulting in modulation of transmitted intensity. Remarkably, we achieve a maximum modulation of -6.20 dB with an ultra-short modulation length of 2 μm. Our MZ modulator boasts an ultra-compact footprint area of ~30 μm² and a thin thickness of 18 nm. Our findings present new opportunities for the advancement of highly integrated and efficient photonic devices utilizing van der Waals materials.

Abstract

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