Harats Moshe G, Schwarz Ilai, Zimran Adiel, Banin Uri, Chen Gang, Rapaport Ronen
Racah Institute of Physics, The Hebrew University of Jerusalem, Jerusalem, Israel.
Opt Express. 2011 Jan 17;19(2):1617-25. doi: 10.1364/OE.19.001617.
We show a large enhancement of two-photon absorption processes in nanocrystal quantum dots and of light upconversion efficiency from the IR to the near-IR spectral regime, using a hybrid optical device in which near-IR emitting InAs quantum dots were embedded on top a metallic nanoslit array. The resonant enhancement of these nonlinear optical processes is due to the strong local electromagnetic field enhancements inside the nanoslit array structure at the extraordinary transmission resonances. A maximal two-photon absorption enhancement of more than 20 was inferred. Different high field regions were identified for different polarizations, which can be used for designing and optimizing efficient nonlinear processes in such hybrid structures. Combining nanocrystal quantum dots with subwavelength metallic nanostructures is therefore a promising way for a range of possible nonlinear optical devices.
我们展示了在纳米晶体量子点中双光子吸收过程的大幅增强，以及从红外到近红外光谱区域的光上转换效率的提高，这是通过一种混合光学器件实现的，其中近红外发射的InAs量子点被嵌入到金属纳米狭缝阵列之上。这些非线性光学过程的共振增强是由于在异常透射共振时纳米狭缝阵列结构内部强烈的局部电磁场增强。推断出最大双光子吸收增强超过20。针对不同偏振识别出了不同的高场区域，这可用于设计和优化此类混合结构中的高效非线性过程。因此，将纳米晶体量子点与亚波长金属纳米结构相结合是实现一系列可能的非线性光学器件的一种有前景的方法。
