The successful demonstration of an optical fiber-coupled terahertz time–domain spectroscopy (THz-TDS) system is described in this study. The terahertz output power of the emitter with two optical band rejection filters was 132 nW, which is an improvement of 70% over the output power without any filters. This improvement is due to the suppression of an optical modulated signal that is reverse-generated when an alternating current bias exceeding a certain threshold is applied to the emitter. Under the optimal alignment conditions, the terahertz detector in a fiber-coupled THz-TDS system clearly measured water vapor dips in the free space.
© 2011 Optical Society of America
Original Manuscript: May 10, 2011
Revised Manuscript: July 11, 2011
Manuscript Accepted: July 15, 2011
Published: August 8, 2011
Sang-Pil Han, Hyunsung Ko, Namje Kim, Han-Cheol Ryu, Chul Wook Lee, Young Ahn Leem, Donghun Lee, Min Yong Jeon, Sam Kyu Noh, Hyang Sook Chun, and Kyung Hyun Park, "Optical fiber-coupled InGaAs-based terahertz time–domain spectroscopy system," Opt. Lett. 36, 3094-3096 (2011)