Transmittance investigation on capacitive mesh on thick dielectric substrates as output windows for optically pumped terahertz lasers

作     者：祁春超 左都罗 卢彦兆 唐建 程祖海 

作者机构：Wuhan National Laboratory for OptoelectronicsCollege of Optoelectronic Science and EngineeringHuazhong University of Science and Technology 

出 版 物：《Chinese Physics B》 (中国物理B（英文版）)

年 卷 期：2010年第19卷第11期

页      面：389-394页

核心收录：

学科分类：080901[工学-物理电子学] 0809[工学-电子科学与技术（可授工学、理学学位）] 08[工学] 080401[工学-精密仪器及机械] 0804[工学-仪器科学与技术] 0803[工学-光学工程] 

基　　金：Project supported by the Creative Foundation of Wuhan National Laboratory for Optoelectronics (Grant No. Z080007) partly by the National Basic Research Program of China (973 Program)(Grant No. 61328) 

主　　题：physical optics capacitive mesh structure output coupler optically pumped Terahertz laser 

摘      要：This paper reports that an output window for optically pumped terahertz （THz） laser has been fabricated by depositing a capacitive nickel-mesh on a thick high-resistivity silicon substrate （approximating to 5 mm thick）. Unlike the conventional process of depositing a gold film approximating to 100 nm on negative photoresist using electron-beam evaporation, a nickel film approximating to 1.5 μm thick is directly deposited on the clean surface of dielectric substrate using magnetron sputtering and then a positive photoresist is spun onto the nickel metal surface at 6000 r for 60 s. A transmittance spectrum of the output window in a certain frequency range （say, from zero to 1 THz） has been obtained by using THz time domain spectroscopy. Moreover a transmittance spectrum simulated numerically has also been estimated with respect to the output window using the transmission-line model （TLM） containing attenuation component from dielectric substrate. The simulation results show that the TLM can explain well the experimental curve in a certain frequency range from zero to 1 THz. Thus it is demonstrated that the improved optical component can be efficiently used as both output coupler and output window for optically pumped THz lasers.