提出并设计了一种用于真空中操控亚波长微粒的可调控渐变狭缝光子晶体波导结构.该结构利用光力将微粒捕获到狭缝中, 使其沿光传输方向传输, 并通过外加折射率调控的方式, 将微粒输运到所需位置.分析了狭缝光子晶体波导的带隙结构、传输特性与微粒的受力情况, 计算了热调控光子晶体波导的功耗与温度分布.结果表明, 利用狭缝宽度渐变的硅基光子晶体波导, 通过热调控改变硅折射率, 可以实现光波截止位置从出射端到入射端的移动; 对于总长度18 μm的狭缝光子晶体波导, 从入射端到出射端狭缝缩窄4 nm时, 控制微粒位置所需的折射率变化为0.012, 而改变折射率所需的加热功率不高于13.7 mW.这一结构将为微粒操控提供一种可能的实现方案.

A tunable gradual changed Slotted Photonic Crystal Waveguide (S-PCW) was demonstrated based on subwavelength particle controller for vacuum environment. Particles can be trapped in slot structure and transported along the light transmission direction. Through thermal-optic tuning the gradual changed S-PCW, particles can be transported to the desired position. The bandgap structure and transmission characteristics of the S-PCW were analyzed, as well as the optical force with the particle. The simulation results on the power consumption of the thermal control and the temperature distribution in S-PCW show that the particle transportation in a gradual changed silicon S-PCW can be achieved through thermal-tuning the refractive index of silicon material. The calculated refractive index shift is 0.012 for position control in a 18 μm-long S-PCW with 4 nm slot width shift fron input port to output port, which corresponding to a 13.7 mW heating power. The compact device footprint shows the potential of the controller for micro manipulating applications.