Lu Xiyuan, Moille Gregory, Rao Ashutosh, Westly Daron, Srinivasan Kartik
Microsystems and Nanotechnology Division, Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA.
Institute for Research in Electronics and Applied Physics and Maryland NanoCenter, University of Maryland, College Park, MD 20742, USA.
Optica. 2020;7(10). doi: 10.1364/optica.393810.
The on-chip generation of coherent, single-frequency laser light that can be tuned across the visible spectrum would help enable a variety of applications in spectroscopy, metrology, and quantum science. Recently, third-order optical parametric oscillation (OPO) in a microresonator has shown great promise as an efficient and scalable approach towards this end. However, considering visible light generation, so far only red light at < 420 THz (near the edge of the visible band) has been reported. In this work, we overcome strong material dispersion at visible wavelengths and demonstrate on-chip OPO in a SiN microresonator covering >130 THz of the visible spectrum, including red, orange, yellow, and green wavelengths. In particular, using an input pump laser that is scanned 5 THz in the near-infrared from 386 THz to 391 THz, the OPO output signal is tuned from the near-infrared at 395 THz to the visible at 528 THz, while the OPO output idler is tuned from the near-infrared at 378 THz to the infrared at 254 THz. The widest signal-idler separation of 274 THz is more than an octave in span and is the widest demonstrated for a nanophotonic OPO to date. More generally, our work shows how nonlinear nanophotonics can transform light from readily accessible compact near-infrared lasers to targeted visible wavelengths of interest.
能够在可见光谱范围内进行调谐的相干单频激光的片上产生，将有助于实现光谱学、计量学和量子科学等领域的各种应用。最近，微谐振器中的三阶光学参量振荡（OPO）作为实现这一目标的一种高效且可扩展的方法，已展现出巨大潜力。然而，就可见光产生而言，到目前为止，仅报道了低于420太赫兹（接近可见波段边缘）的红光。在这项工作中，我们克服了可见波长下强烈的材料色散，并在覆盖超过130太赫兹可见光谱（包括红、橙、黄和绿波长）的氮化硅微谐振器中演示了片上OPO。特别是，使用一个在近红外波段从386太赫兹到391太赫兹扫描5太赫兹的输入泵浦激光器，OPO输出信号从395太赫兹的近红外波段调谐到528太赫兹的可见光波段，而OPO输出闲频光则从378太赫兹的近红外波段调谐到254太赫兹的红外波段。274太赫兹的最大信号 - 闲频光分离跨度超过一个倍频程，是迄今为止纳米光子OPO所展示的最大跨度。更一般地说，我们的工作展示了非线性纳米光子学如何将来自易于获取的紧凑型近红外激光器的光转换为感兴趣的目标可见波长。
