Singh Neetesh, Xin Ming, Vermeulen Diedrik, Shtyrkova Katia, Li Nanxi, Callahan Patrick T, Magden Emir Salih, Ruocco Alfonso, Fahrenkopf Nicholas, Baiocco Christopher, Kuo Bill P-P, Radic Stojan, Ippen Erich, Kärtner Franz X, Watts Michael R
Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
John A. Paulson School of Engineering and Applied Science, Harvard University, Cambridge, MA 02138, USA.
Light Sci Appl. 2018 Jan 26;7:17131. doi: 10.1038/lsa.2017.131. eCollection 2018.
Efficient complementary metal-oxide semiconductor-based nonlinear optical devices in the near-infrared are in strong demand. Due to two-photon absorption in silicon, however, much nonlinear research is shifting towards unconventional photonics platforms. In this work, we demonstrate the generation of an octave-spanning coherent supercontinuum in a silicon waveguide covering the spectral region from the near- to shortwave-infrared. With input pulses of 18 pJ in energy, the generated signal spans the wavelength range from the edge of the silicon transmission window, approximately 1.06 to beyond 2.4 μm, with a -20 dB bandwidth covering 1.124-2.4 μm. An octave-spanning supercontinuum was also observed at the energy levels as low as 4 pJ (-35 dB bandwidth). We also measured the coherence over an octave, obtaining , in good agreement with the simulations. In addition, we demonstrate optimization of the third-order dispersion of the waveguide to strengthen the dispersive wave and discuss the advantage of having a soliton at the long wavelength edge of an octave-spanning signal for nonlinear applications. This research paves the way for applications, such as chip-scale precision spectroscopy, optical coherence tomography, optical frequency metrology, frequency synthesis and wide-band wavelength division multiplexing in the telecom window.
对高效的基于互补金属氧化物半导体的近红外非线性光学器件有着强烈需求。然而，由于硅中的双光子吸收，许多非线性研究正转向非传统光子学平台。在这项工作中，我们展示了在覆盖从近红外到短波红外光谱区域的硅波导中产生倍频程相干超连续谱。输入能量为18 pJ的脉冲时，产生的信号跨越从硅传输窗口边缘（约1.06 μm）到超过2.4 μm的波长范围，其 -20 dB带宽覆盖1.124 - 2.4 μm。在低至4 pJ的能量水平下也观察到了倍频程超连续谱（-35 dB带宽）。我们还测量了一个倍频程上的相干性，得到的结果与模拟结果吻合良好。此外，我们展示了对波导三阶色散的优化以增强色散波，并讨论了在倍频程信号的长波长边缘处有一个孤子用于非线性应用的优势。这项研究为诸如芯片级精密光谱学、光学相干断层扫描、光学频率计量、频率合成以及电信窗口中的宽带波分复用等应用铺平了道路。
