Laser Physics Laboratory

Our research interests are in the field of terahertz spectroscopy. The terahertz (THz) spectral region was sometimes called the gap in the electromagnetic spectrum because it was difficult to produce tunable, coherent terahertz radiation. Recent development of semiconductor and laser technologies, however, enables us to generate and control terahertz-wave more easily. In our laboratory, two types of terahertz spectrometers are working. One is based on terahertz time-domain spectroscopy (THz-TDS). A single measurement gives the whole spectrum of the 1-3 THz region. We currently observe the spectra of biologically-relevant molecules such as sugar group and amino acids. The other spectrometer based on the difference frequency of two near-infrared semiconductor lasers provides high-resolution spectra of gas-phase molecules such as methanol and water vapor. Quite recently, we also have begun to combine these spectrometers with manipulation of microparticles and molecules to improve the resolution of observed spectra.

CO2 Laser for trapping of a microparticle