基于混合微腔的高效率太赫兹波产生

1)深圳大学电子与信息工程学院,广东深圳 518060; 2)深圳大学太赫兹技术研究中心,广东深圳 518060; 3)深圳大学光电子器件与系统教育部/广东省重点实验室,广东深圳 518060

非线性光学; 光学差频; 回音壁模; 表面等离激元; 亚波长局域; 太赫兹波产生

Efficient terahertz wave generation based on hybrid micro-cavity
LIU Qiang1, 2, WANG Qiong1, 2, and OUYANG Zhengbiao1, 2, 3

1)College of Electronic and Information Engineering, Shenzhen University, Shenzhen 518060, Guangdong Province, P.R.China2)THz Technical Research Center, Shenzhen University, Shenzhen 518060, Guangdong Province, P.R.China3)Key Laboratory of Optoelectronics Devices and Systems of Ministry of Education and Guangdong Province, Shenzhen University, Shenzhen 518060, Guangdong Province, P.R.China

nonlinear optics; optical frequency-difference effect; whispering gallery mode; surface plasmonic mode; sub-wavelength confinement; terahertz wave generation

DOI: 10.3724/SP.J.1249.2019.02140

备注

提出并研究基于回音壁共振模和表面等离子激元共振模的混合微腔太赫兹产生系统,运用有限元方法模拟实现了室温下11.7 THz的太赫兹波产生,所获得的太赫兹波模体积小,超过衍射极限,亚波长局域使得Purcell因子达到7.2×103(砷化镓中太赫兹波长的负三次方). 研究表明,该结构的太赫兹波转化效率可达到量子极限(~5.5%),太赫兹波的最高输出功率可达166.3 mW. 该系统可在室温下工作,转化效率接近量子极限,太赫兹输出功率较高,且易于光学集成.

By utilizing the nonlinear optical frequency-difference effect, an efficient terahertz(THz)wave generator based on a hybrid micro-cavity of whispering gallery(WG)mode and surface plasmonic mode is proposed and investigated. Simulations based on finite element method are performed. It is found that the THz wave at the frequency 11.7 THz can be produced at room temperature, and the terahertz modal volume is small, which breaks the diffraction limit, the sub-wavelength confinement in turn produces a high Purcell factor up to 7.2×103(one in cubic of the THz wavelength in GaAs). Further studies show that the conversion efficiency can reach the quantum limit(~5.5%), and the maximum output of the generated THz wave is as high as 166.3 mW. The advantages of the design include: capability for operation at room temperature, high conversion efficiency that approaches to the quantum limit, high output power for the THz wave, and convenience for all-optical integration.

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