Abbasi Mohammad Mahdi, Darbari Sara, Moravvej-Farshi Mohammad Kazem
Opt Express. 2019 Sep 16;27(19):26648-26660. doi: 10.1364/OE.27.026648.
Using a plasmonic graphene ring resonator of resonant frequency 10.38 THz coupled to a plasmonic graphene waveguide, we design a lab-on-a-chip optophoresis system that can function as an efficient plasmonic force switch. Finite difference time domain numerical simulations reveal that an appropriate choice of chemical potentials of the waveguide and ring resonator keeps the proposed structure in on-resonance condition, enabling the system to selectively trap a nanoparticle. Moreover, a change of 250 meV in the ring chemical potential (i.e., equivalent to 2.029 V change in the corresponding applied bias) switches the structure to a nearly perfect off-resonance condition, releasing the trapped particle. The equivalent plasmonic switch ON/OFF ratio at the waveguide output is -15.519 dB. The designed system has the capability of trapping, sorting, controlling, and separating PS nanoparticles of diameters ≥30 nm with a THz source intensity of 14.78 mW/µm and ≥22 nm with 29.33 mW/µm.
通过使用共振频率为10.38太赫兹的等离子体石墨烯环形谐振器与等离子体石墨烯波导耦合，我们设计了一种芯片实验室光泳系统，该系统可作为一种高效的等离子体力开关。时域有限差分数值模拟表明，对波导和环形谐振器的化学势进行适当选择可使所提出的结构保持在共振状态，从而使系统能够选择性地捕获纳米粒子。此外，环形化学势变化250毫电子伏特（即相当于相应施加偏压变化2.029伏）会将结构切换到几乎完美的非共振状态，释放被捕获的粒子。波导输出端的等效等离子体开关开/关比为-15.519分贝。所设计的系统能够在太赫兹源强度为14.78毫瓦/微米时捕获、分类、控制和分离直径≥30纳米的聚苯乙烯纳米粒子，在太赫兹源强度为29.33毫瓦/微米时捕获、分类、控制和分离直径≥22纳米的聚苯乙烯纳米粒子。
