The development of terahertz wave air-plasma photonics instrumentation is crucial for the advanced research of intense broadband THz wave generation and detection in laser-induced air-plasma, remote THz sensing, and nonlinear THz spectroscopy. Our proposed instrument will unlock research by exploring the physical mechanisms for THz generation and detection under extreme conditions (E-field strength) with unparalleled breadth of frequency bandwidth, sensitivity, and remote detection capability. A focused optical pulse (mJ pulse energy and <30 femtosecond pulse duration) in gas creates a plasma, which produces THz waves in the far field. Using either air-breakdown-coherent-detection (ABCD) or THz-enhanced-fluorescence (TEF) methods, this plasma can also detect pulsed THz waves with potential standoff sensing capability.
Intellectual merit: Ambient air, when excited with intense femtosecond laser beams, exhibits a remarkable ability to generate and detect pulsed THz waves through an optical nonlinear process. The use of air (or selected gases) as a broadband THz wave emitter and THz wave sensor provides superior bandwidth (0.1 - 30 THz), sensitivity (heterodyne), resolution ( Broader impact: Our proposed THz air-plasma photonics system will provide a key instrument that will enable interdisciplinary research and advance numerous THz wave sensing and imaging developments. This instrument will be one of the major shared instruments in the THz Center for eleven faculty members, and over 50 students and senior researchers, and will be made available to our national and international collaborators from around the globe.
