Efficient High-Power Tunable Terahertz Sources using Optical Techniques

The main objective of the proposed Phase II project is to leverage the technology of THz generation in resonantly-pumped quasi-phase-matched (QPM) GaAs structures, jointly developed by Stanford University and Microtech Instruments, Inc., and create a compact and power-efficient commercial THz source with a mW-level average power. This source will be continuously or step-tunable in the 0.5-3 THz range and will use a compact fiber laser as a pump source. This small-size and maintenance-free instrument will be useful for a big variety of applications including THz imaging and spectroscopy. BENEFIT: There is a colossal potential for exploiting terahertz waves (1 THz = 1012 Hz, ƒÜ=300 ƒÝm) in the fields extending far beyond the realms of their traditional use, like astronomy, study of Earth¡¦s atmosphere, high-resolution spectroscopy and plasma diagnostics. These new applications emerged in the last two decades and encompass ¡¥friendly X-rays¡¦ real-time imaging (THz radiation experiences, in many occasions, much smaller scattering than the optical, and thus can penetrate many materials; yet the photon energy is too small to do any harm to living organisms), sensing and spectroscopic imaging by means of rotational-vibrational spectroscopy, because of extreme richness of absorption ¡¥fingerprints¡¦ in the THz range, biomedical imaging (identifying cancers, particularly skin cancer), pharmaceutical industry (classifying molecular polymorphs), as well as broadband wireless communication. Another emerging field is nonlinear interactions of THz waves with matter and nonlinear terahertz spectroscopy.