利用激光诱导荧光来探测远程宽带太赫兹波

Remote terahertz wave sensing using laser-induced fluorescence

远程太赫兹光谱分析在国土安全和环境监测方面的应用有着巨大的潜力.然而由于大气中的水气在太赫兹频率范围内的强吸收,远程宽带太赫兹探测一直以来都是一个挑战.文章介绍了一种通过相干控制非对称电离气体荧光来实现远程宽带探测太赫兹波的全光学技术.由于荧光在大气中的高透过率以及全方位辐射特性,该技术可用于太赫兹波的远程探测,具有最小水气吸收以及不受光信号收集方向限制两个优点.实验上已经获得了距离为10m量级的太赫兹波相干探测.

Remote terahertz（THz） wave spectroscopy holds great potential in the applications in homeland security and environmental monitor.However,broadband THz wave sensing at standoff distance has remained long-existing challenge due to the strong ambient water vapor absorption in THz frequency region.Here we present an ＂all-optical＂ technique of broadband terahertz wave remote sensing through coherent manipulation of the fluorescence emission from asymmetrically ionized gases.Owing to the high atmospheric transparency and omni-directional emission pattern of fluorescence,this technique can be used for remote sensing with advantages of minimal water vapor attenuation and unlimited directionality for optical signal collection.Coherent THz wave detection at a distance of 10 meters has been successfully demonstrated.