Variable angle terahertz impulse ranging on cylinders

Summary form only given. Optoelectronically generated freely propagating terahertz (THz) impulse ranging experiments have been demonstrated. The subpicosecond resolution permits temporal isolation of scattering mechanisms. Limitations of previously demonstrated systems are the fixed bistatic angle between the transmitter and receiver and wide aperture associated with the collection optics of the receiver reducing resolution. The configuration reported overcomes these limitations by introducing a freely positionable receiver allowing a wide range of detection angles (21/spl deg/ to 180/spl deg/) and by using a small aperture receiver allowing the use of plane wave approximations. Both capabilities are important for investigating complex near-resonant targets. This impulse ranging system discussed is a modification of the THz beam system used for THz time-domain spectroscopy. The angle /spl theta/ between the transmitter and the receiver can be continuously adjusted.