传统鬼成像利用两路光的位置-位置或动量-动量关联特性实现。当光束沿单模光纤传输时,这些关联特性是无法保持的,因此传统鬼成像无法通过单模光纤长距离传输实现。在自发非线性参量过程产生的信号光子和闲频光子之间,以及在热光分束后形成的两束光之间存在频率关联特性,这种关联特性可以在光纤传输过程中稳定保持,基于此可以实现长距离光纤传送的时域鬼成像。这些工作拓展了鬼成像的实现方法,为大地理尺度下鬼成像的应用拓展了新思路。本文综述了基于频率关联的长距离光纤传输时域鬼成像的原理和实现方法,介绍了一种时域鬼成像的典型应用——量子安全鬼成像,最后对时域鬼成像的前景进行了展望。

Conventional ghost imaging is achieved by the position--position or momentum--momentum correlation between two beams. These correlations cannot be preserved when the beams propagate along single-mode optical fibers. Thus, conventional ghost imaging cannot be achieved distantly over single-mode fibers. Frequency correlations between signal photons and idler photons generated from the spontaneous nonlinear parametric process or between two light beams from the same thermal light source are noted. The frequency correlation can be stably preserved over optical fibers. Thus, we propose and demonstrate long-distance temporal ghost imaging schemes over optical fibers based on frequency correlations in correlated photon pairs and thermal light beams. This work extends the method for achieving ghost imaging, providing new ideas for applying ghost imaging over a large geographical scale. In this study, we review the principles and methods for quantum and thermal temporal ghost imaging over optical fibers. We introduce an application of temporal ghost imaging—quantum secure ghost imaging. Furthermore, a perspective on the development of temporal ghost imaging is provided.