硅基光子晶体微流通道增强荧光定向远场发射

Enhanced Far-Field Fluorescence Emission using Silicon-Based Photonic Crystal Microfluidic Channels

摘要:

本文提出了一种基于硅基光子晶体的微流通道,有效增强了通道内的激发光场并且量子点的发射光在光子晶体形成的共振腔内得到了谐振增强。根据平面波展开法计算了光子晶体的能带。利用时域有限差分法详细研究了微流通道内量子点偏振,通道结构,以及量子点位置对于荧光发射的影响,并对该结构在激发过程的增强效果进行了分析。光子晶体微流通道具有比传统硅微流通道更高的远场发射功率以及更窄的辐射角。与裸玻璃相比,光子晶体微流通道中的量子点的远场功率实现了16.9倍的增强以及9°以内发射角。对于945 nm的激发光实现了通道内平均7.9倍的增强。

Abstract:

In this paper, a silicon-based photonic crystal microfluidic channel is proposed, which effectively enhances the excitation light field in the channel, and the emitted light of quantum dots is resonantly enhanced in the resonant cavity formed by the photonic crystal. The photonic bandgap of photonic crystal is calculated by the plane wave expansion method. The effects of quantum dot pol-arization, different structures, and quantum dot positions on fluorescence emission are studied by usi-ng the finite difference time-domain method, and the enhancement effect of the structure in the excit-ation process is analyzed. Photonic crystal microfluidic channels have higher far-field emission power and narrower radiation angles than conventional silicon microfluidic channels. Compared to the glass substrate, the far-field emission power of quantum dots in the microfluidic channel is enhanced by a factor of 16.9 and the emission angle within 9° is achieved. An average of 7.9-fold enhancement is achieved at 945 nm in the channel.