Nitiss Edgars, Yakar Ozan, Stroganov Anton, Brès Camille-Sophie
Opt Lett. 2020 Apr 1;45(7):1958-1961. doi: 10.1364/OL.387603.
The availability of nonlinear parametric processes, such as frequency conversion in photonic integrated circuits is essential. In this contribution, we demonstrate a highly tunable second-harmonic generation in a fully complementary metal-oxide-semiconductor (CMOS)-fabrication-compatible silicon nitride integrated photonic platform. We induce the second-order nonlinearity using an all-optical poling technique with the second-harmonic light generated in the fundamental mode, and a narrow quasi-phase matching (QPM) spectrum by avoiding higher-order mode mixing. We are then able to broadly tune the phase-matched pump wavelength over the entire C-band (1540 nm to 1560 nm) by varying the poling conditions. Fine-tuning of QPM is enabled by thermo-optic effect with the tuning slope / in our device being 113.8 pm/°C. In addition, we exploit the measurable variation of the 3 dB QPM bandwidth to confirm how the length of the all-optically inscribed grating varies with exposure time.
诸如光子集成电路中的频率转换等非线性参数过程的可用性至关重要。在本论文中，我们展示了在完全与互补金属氧化物半导体（CMOS）制造兼容的氮化硅集成光子平台中实现的高度可调谐二次谐波产生。我们使用全光极化技术，利用基模中产生的二次谐波光来诱导二阶非线性，并通过避免高阶模混合实现窄的准相位匹配（QPM）光谱。然后，通过改变极化条件，我们能够在整个C波段（1540纳米至1560纳米）上广泛调谐相位匹配泵浦波长。通过热光效应实现了QPM的微调，我们器件中的调谐斜率为113.8皮米/°C。此外，我们利用3 dB QPM带宽的可测量变化来确认全光写入光栅的长度如何随曝光时间变化。
