Ultra-compact, broadband adiabatic passage optical couplers in thin-film lithium niobate on insulator waveguides

Lin YX, Younesi M, Chung HP, Chiu HK, Geiss R, Tseng QH, Setzpfandt F, Pertsch T, Chen YH (2021)

Publication Type: Journal article

Publication year: 2021

Journal

Optics Express Optical Society of America

Book Volume: 29

Pages Range: 27362-27372

Journal Issue: 17

DOI: 10.1364/OE.435633

Abstract

We report the first demonstration of broadband adiabatic directional couplers in thin-film lithium niobate on insulator (LNOI) waveguides. A three LN-waveguide configuration with each waveguide having a ridge cross section of less than 1 square micron, built atop a layer of SiO2 based on a 500-µm-thick Si substrate, has been designed and constructed to optically emulate a three-state stimulated Raman adiabatic passage system, with which a unique counterintuitive adiabatic light transfer phenomenon in a high coupling efficiency of >97% (corresponding to a >15 dB splitting ratio) spanning telecom S, C, and L bands for both TE and TM polarization modes has been observed for a 2-mm long coupler length. An even broader operating bandwidth of >800 nm of the device can be found from the simulation fitting of the experimental data. The footprint of the realized LNOI adiabatic coupler has been reduced by >99% compared to its bulk counterparts. Such an ultra-compact, broadband LNOI adiabatic coupler can be further used to implement or integrate with various photonic elements, a potential building block for realizing large-scale integrated photonic (quantum) circuits in LN.

Involved external institutions

National Central University TW Taiwan (TW) Friedrich-Schiller-Universität Jena DE Germany (DE) Taiwan Semiconductor Research Institute (TSRI) / 國家實驗研究院台灣半導體研究中心 TW Taiwan (TW)

How to cite

APA:

Lin, Y.-X., Younesi, M., Chung, H.-P., Chiu, H.-K., Geiss, R., Tseng, Q.-H.,... Chen, Y.-H. (2021). Ultra-compact, broadband adiabatic passage optical couplers in thin-film lithium niobate on insulator waveguides. Optics Express, 29(17), 27362-27372. https://doi.org/10.1364/OE.435633

MLA:

Lin, Yi-Xin, et al. "Ultra-compact, broadband adiabatic passage optical couplers in thin-film lithium niobate on insulator waveguides." Optics Express 29.17 (2021): 27362-27372.

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