An integrated 3C-silicon carbide-on-insulator photonic platform for nonlinear and quantum light sources
Jiayang Li, Qianni Zhang, Jiantao Wang, Andrew W. Poon
Abstract
Abstract Silicon carbide (SiC) polytypes are emerging for integrated nonlinear and quantum photonics due to their wide-bandgap energies, second-order optic nonlinearity and process compatibility with complementary metal-oxide-semiconductor technologies. Among polytypes, 3C-SiC is the only one epitaxially grown on wafer-scale silicon substrates. However, on-chip nonlinear and quantum light sources leveraging the second-order nonlinearity of 3C-SiC have not been reported to our knowledge. Here, we design and fabricate an elliptical microring on 3C-SiC. We demonstrate a nonlinear light source with a second-harmonic generation efficiency of $$17.4\pm 0.2 \% {W}^{-1}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mn>17.4</mml:mn> <mml:mo>±</mml:mo> <mml:mn>0.2</mml:mn> <mml:mi>%</mml:mi> <mml:msup> <mml:mrow> <mml:mi>W</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:msup> </mml:math> and difference-frequency generation with a signal-idler bandwidth of 97 nm. We demonstrate a spontaneous parametric down-conversion source with a photon-pair generation rate of 4.8 MHz and a coincidence-to-accidental ratio of $$3361\pm 84$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mn>3361</mml:mn> <mml:mo>±</mml:mo> <mml:mn>84</mml:mn> </mml:math> . We measure a low heralded single-photon second-order coherence $${g}_{H}^{\left(2\right)}=0.0007$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msubsup> <mml:mrow> <mml:mi>g</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>H</mml:mi> </mml:mrow> <mml:mrow> <mml:mfenced> <mml:mrow> <mml:mn>2</mml:mn> </mml:mrow> </mml:mfenced> </mml:mrow> </mml:msubsup> <mml:mo>=</mml:mo> <mml:mn>0.0007</mml:mn> </mml:math> . We observe time-bin entanglement with a visibility of $$86.0\pm 2.4 \%$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mn>86.0</mml:mn> <mml:mo>±</mml:mo> <mml:mn>2.4</mml:mn> <mml:mi>%</mml:mi> </mml:math> using this source. Our work paves a way toward SiC-based on-chip nonlinear and quantum photonic circuits.