In this Letter, we report the second harmonic generation (SHG) in a colloidal solution of CdSe/CdS nanoplatelets (NPLs) in the case of two-photon excitation in the region of exciton transition from the light holes sub-band to the conduction sub-band (549 nm, 1lh-1e) by femtosecond laser pulses (1064 nm, 100 kHz). Discovery of the SHG in colloidal solutions of NPLs opens up new perspectives for their use as biomarkers or for optical imaging, since in contrast to two-photon photoluminescence the SHG can increase both spectral and temporal resolution by several orders of magnitude. The SHG is also extremely important to consider when designing two-photon pumping lasers.

在这封信中，我们报告了在从光孔子带到传导子的激子跃迁区域中的双光子激发的情况下，CdSe / CdS纳米血小板（NPLs）的胶体溶液中的二次谐波产生（SHG）飞秒激光脉冲（1064 nm，100 kHz）的高波段（549 nm，1lh-1e）。在不良贷款的胶体溶液中发现SHG为它们用作生物标记物或光学成像开辟了新的前景，因为与双光子光致发光相比，SHG可以将光谱和时间分辨率提高几个数量级。设计双光子泵浦激光器时，SHG也非常重要。