无加热无激光泵浦的激发态原子滤光器技术

Atomic filter is a kind of quantum optical spectrum filter taking use of atomic transition lines, and can be used in free space optical communication, optical imaging, lidar, and quantum key distribution in free space. The working wavelength of atomic filter depends on the transition lines of corresponding atoms. Based on the difference of atomic states used for these transitions, atomic filters can be categorized into ground-state atomic filters and excited-state atomic filters. Since there are much more possible wavelengths, including infrared spectrum, for transitions between excited state, excited-state atomic filters appears to be very important and are studied a lot in recent years. However, there are two major limitations for excited-state atomic filters. First, heating is usually required for high atomic vapor density, thus the high temperature infrared radiation limits its applications. Second, laser pumping is usually used for excited-state atom preparation, thus the optical aperture is limited by the width of the pumping laser beam. Hollow cathode lamp can prepare exited state atomic vapor by accelerating ionized noble gas to sputter off atoms from the cathode, which has potential to solve the above problem in principle. In this proposal, a new excited-state atomic filter based on hollow cathode lamp is suggested to solve the above problems, which has great significance for atomic filters, especially for infrared applications.

原子滤光器是一种利用原子能级间量子跃迁的精细光谱实现超窄带宽滤光功能的量子光学器件，它在空间光通信、光学成像、激光雷达、空间量子密钥分发等领域有良好的应用。原子滤光器的工作波长取决于原子能级间量子跃迁的特征波长，根据利用的原子能级不同分为基态和激发态两类。由于激发态跃迁有红外光谱在内的更丰富波长选择，激发态原子滤光器是近年来重要的研究方向。然而，激发态原子滤光器通常存在两个瓶颈问题：一是需对原子气室加热以得到高密度饱和蒸汽，高温和红外辐射对部分应用不利；二是激发态原子制备，需额外能量将原子泵浦到激发态，目前主要使用激光实现，激光光束宽度严重限制了其通光口径。空心阴极灯通过电离的高速惰性气体轰击阴极物质直接形成激发态原子气体，原理上具备解决上述问题的潜力。本项目提出了利用空心阴极灯的激发态原子滤光器新方案，希望有效解决上述瓶颈问题，对推动原子滤光器往近红外乃至中红外波段的应用具有重要意义。

原子滤光器是一种利用原子能级间量子跃迁的精细光谱实现超窄带宽滤光功能的量子光学器件，它在空间光通信、光学成像、激光雷达、空间量子密钥分发等领域有良好的应用。原子滤光器的工作波长取决于原子能级间量子跃迁的特征波长，根据利用的原子能级不同分为基态和激发态两类。由于激发态跃迁有红外光谱在内的更丰富波长选择，激发态原子滤光器是近年来重要的研究方向。然而，激发态原子滤光器通常存在两个瓶颈问题：一是需对原子气室加热以得到高密度饱和蒸汽，高温和红外辐射对部分应用不利；二是激发态原子制备，需额外能量将原子泵浦到激发态，目前主要使用激光实现，激光光束宽度严重限制了其通光口径。空心阴极灯通过电离的高速惰性气体轰击阴极物质直接形成激发态原子气体，原理上具备解决上述问题的潜力。.本项目提出了并实现了利用空心阴极灯的激发态原子滤光器新方案，验证了其在低温条件下的工作性能，该成果首次实现了一种无需加热和外部光学泵浦的新型原子滤光器，为简化原子滤光器结构，拓展其应用范围提供了一种创新性方案。此外，本项目对各类型激发态原子滤光器进行了对比研究，还对原子滤光器应用于法拉第激光器等具体应用情况进行了针对性研究，为不同应用场景下的原子滤光器方案选择提供了参考，对推动原子滤光器往近红外乃至中红外波段的应用具有重要意义。