TY - JOUR
T1 - Large optical nonlinearity enabled by coupled metallic quantum wells
AU - Qian, Haoliang
AU - Li, Shilong
AU - Chen, Ching Fu
AU - Hsu, Su Wen
AU - Bopp, Steven Edward
AU - Ma, Qian
AU - Tao, Andrea R.
AU - Liu, Zhaowei
N1 - Funding Information:
This research is financially supported by the National Science Foundation, Division of Material Research (NSF-DMR-1610538), and DARPA DSO-NLM Program (Grant No. HR00111820038). S.L. acknowledges the financial support of the International Postdoctoral Exchange Fellowship Program (No. 20170010).
Publisher Copyright:
© 2019, The Author(s).
PY - 2019/12/1
Y1 - 2019/12/1
N2 - New materials that exhibit strong second-order optical nonlinearities at a desired operational frequency are of paramount importance for nonlinear optics. Giant second-order susceptibility χ (2) has been obtained in semiconductor quantum wells (QWs). Unfortunately, the limited confining potential in semiconductor QWs causes formidable challenges in scaling such a scheme to the visible/near-infrared (NIR) frequencies for more vital nonlinear-optic applications. Here, we introduce a metal/dielectric heterostructured platform, i.e., TiN/Al 2 O 3 epitaxial multilayers, to overcome that limitation. This platform has an extremely high χ (2) of approximately 1500 pm/V at NIR frequencies. By combining the aforementioned heterostructure with the large electric field enhancement afforded by a nanostructured metasurface, the power efficiency of second harmonic generation (SHG) achieved 10 −4 at an incident pulse intensity of 10 GW/cm 2 , which is an improvement of several orders of magnitude compared to that of previous demonstrations from nonlinear surfaces at similar frequencies. The proposed quantum-engineered heterostructures enable efficient wave mixing at visible/NIR frequencies into ultracompact nonlinear optical devices.
AB - New materials that exhibit strong second-order optical nonlinearities at a desired operational frequency are of paramount importance for nonlinear optics. Giant second-order susceptibility χ (2) has been obtained in semiconductor quantum wells (QWs). Unfortunately, the limited confining potential in semiconductor QWs causes formidable challenges in scaling such a scheme to the visible/near-infrared (NIR) frequencies for more vital nonlinear-optic applications. Here, we introduce a metal/dielectric heterostructured platform, i.e., TiN/Al 2 O 3 epitaxial multilayers, to overcome that limitation. This platform has an extremely high χ (2) of approximately 1500 pm/V at NIR frequencies. By combining the aforementioned heterostructure with the large electric field enhancement afforded by a nanostructured metasurface, the power efficiency of second harmonic generation (SHG) achieved 10 −4 at an incident pulse intensity of 10 GW/cm 2 , which is an improvement of several orders of magnitude compared to that of previous demonstrations from nonlinear surfaces at similar frequencies. The proposed quantum-engineered heterostructures enable efficient wave mixing at visible/NIR frequencies into ultracompact nonlinear optical devices.
UR - http://www.scopus.com/inward/record.url?scp=85060523514&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85060523514&partnerID=8YFLogxK
U2 - 10.1038/s41377-019-0123-4
DO - 10.1038/s41377-019-0123-4
M3 - Letter
AN - SCOPUS:85060523514
SN - 2095-5545
VL - 8
JO - Light: Science and Applications
JF - Light: Science and Applications
IS - 1
M1 - 13
ER -