A chip-scale second-harmonic source via self-injection-locked all-optical poling  

作　　者：Marco Clementi Edgars Nitiss Junqiu Liu Elena Durán-Valdeiglesias Sofiane Belahsene Hélène Debrégeas Tobias JKippenberg Camille-Sophie Brès 

机构地区：[1]Photonic Systems Laboratory(PHOSL),École Polytechnique Fédérale de Lausanne,1015 Lausanne,Switzerland [2]Laboratory of Photonics and Quantum Measurements(LPQM),École Polytechnique Fédérale de Lausanne,1015 Lausanne,Switzerland [3]Almae Technologies,Route de Nozay,91460 Marcoussis,France

出　　处：《Light(Science & Applications)》2023年第12期2778-2787,共10页光（科学与应用)（英文版）

基　　金：funded by ERC grant PISSARRO(ERC-2017-CoG 771647).

摘　　要：Second-harmonic generation allows for coherently bridging distant regions of the optical spectrum,with applications ranging from laser technology to self-referencing of frequency combs.However,accessing the nonlinear response of a medium typically requires high-power bulk sources,specific nonlinear crystals,and complex optical setups,hindering the path toward large-scale integration.Here we address all of these issues by engineering a chip-scale second-harmonic(SH)source based on the frequency doubling of a semiconductor laser self-injection-locked to a silicon nitride microresonator.The injection-locking mechanism,combined with a high-Q microresonator,results in an ultra-narrow intrinsic linewidth at the fundamental harmonic frequency as small as 41 Hz.Owing to the extreme resonant field enhancement,quasi-phase-matched second-order nonlinearity is photoinduced through the coherent photogalvanic effect and the high coherence is mapped on the generated SH field.We show how such optical poling technique can be engineered to provide efficient SH generation across the whole C and L telecom bands,in a reconfigurable fashion,overcoming the need for poling electrodes.Our device operates with milliwatt-level pumping and outputs SH power exceeding 2 mW,for an efficiency as high as 280%/W under electrical driving.Our findings suggest that standalone,highly-coherent,and efficient SH sources can be integrated in current silicon nitride photonics,unlocking the potential of x(2)processes in the next generation of integrated photonic devices.

关 键 词：RESONATOR HARMONIC INJECTION 

分 类 号：TN2[电子电信—物理电子学]