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Conference on Lasers and Electro-Optics

Ultra-Broadband Spontaneous Parametric Down- Conversion from an Aperiodically-Poled Lithium Niobate Superlattice

Zi S. D. Toa, Anna V. Paterova, Leonid A. Krivitsky

Published Jan 1, 2021• 1 citation
Publisher

Abstract

Ultra-broadband photon pairs from spontaneous parametric down-conversion are important for emerging quantum technologies. Bright ultra-broadband comb-like spectrum spanning ~40 nm around 647 nm signal wavelength from 63.5 mm long aperiodically poled lithium niobate was demonstrated.
DOI
10.1364/cleo_si.2021.stu4c.7

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Broadband nonlinear optical devices play a critical role in both classical and quantum optics. Here, we design and fabricate a 6.82-mm-long step-chirped periodically poled lithium niobate~(CPPLN) waveguide on lithium niobate on insulator, which enables quasi-phase matching over a broad bandwidth for second-harmonic generation~(SHG) and spontaneous parametric down-conversion~(SPDC). The SHG achieves an average efficiency of 54.4\%/W/cm2^22 over the first-harmonic wavelength range of 1510~nm-1620~nm, paving the way for realizing SPDC across a wide range of pump wavelengths. For SPDC, by tuning the pump wavelength to 775~nm, 780~nm, and 785~nm, we achieve broadband photon-pair generation with a maximum full bandwidth and brightness up to 99~THz~(846~nm) and 20~GHz/mW/nm, respectively. Our findings provide an efficient and experiment-friendly approach for generating broadband photon pairs, which holds significant promise for advancing applications in quantum metrology.
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