Fiber-coupled THz spectroscopy for monitoring polymeric compounding processes

摘要

We present a compact, robust, and transportable fiber-coupled THz system for inline monitoring of polymeric compounding processes in an industrial environment. The system is built on a 90cm × 90cm large shock absorbing optical bench. A sealed metal box protects the system against dust and mechanical disturbances. A closed loop controller unit is used to ensure optimum coupling of the laser beam into the fiber. In order to build efficient and stable fiber-coupled antennas we glue the fibers directly onto photoconductive switches. Thus, the antenna performance is very stable and it is secured from dust or misalignment by vibrations. We discuss fabrication details and antenna performance. First spectroscopic data obtained with this system is presented.