Mid-infrared computational temporal ghost imaging

TL;DR

This paper introduces a frequency downconversion method for temporal ghost imaging, enabling imaging in spectral regions like mid-infrared where ultrafast detectors and modulators are unavailable, broadening the technique's applicability.

Contribution

The authors propose a novel frequency downconversion scheme that extends temporal ghost imaging to arbitrary wavelengths, demonstrated in the mid-infrared, without requiring ultrafast detectors.

Findings

Successful demonstration of mid-infrared ghost imaging

Extension of ghost imaging to wavelengths without ultrafast detectors

Potential for ultrafast dynamics studies in challenging spectral regions

Abstract

Ghost imaging in the time domain allows for reconstructing fast temporal objects using a slow photodetector. The technique involves correlating random or pre-programmed probing temporal intensity patterns with the integrated signal measured after modulation by the temporal object. However, the implementation of temporal ghost imaging necessitates ultrafast detectors or modulators for measuring or pre-programming the probing intensity patterns, which is not universally available in all spectral regions especially in the mid-infrared range. Here, we demonstrate a frequency downconversion temporal ghost imaging scheme that enables to extend the operation regime to arbitrary wavelengths regions where fast modulators and detectors are not available. The approach modulates a signal with temporal intensity patterns in the near-infrared and transfers the patterns to an idler via difference-frequency generation at the wavelength of the temporal object to be retrieved. As a proof-of-concept, we demonstrate temporal ghost imaging in the mid-infrared. The scheme is flexible and introduces new possibilities for scan-free pump-probe imaging and the study of ultrafast dynamics in spectral regions where ultrafast modulation or detection is challenging such as the mid-infrared and THz regions.