Temporal ghost imaging using wavelength conversion and two-color detection

Ghost imaging constructs an image by correlating two signals: one that interacts with an object but possesses no spatial information, and the other that contains spatial information but does not interact with the object. Ghost imaging can be extended into the time domain by using laser intensity fluctuations to reconstruct an unknown time-varying pattern, but this requires the measurement of laser fluctuations on ultrafast timescales, a significant limitation at wavelengths where ultrafast detectors are not available. We overcome this by using wavelength conversion to shift the probe laser into a spectral region where ultrafast detectors are available, and we apply this technique to image a temporal object at 2 mu m. Our results demonstrate that temporal correlation information can be transferred to an arbitrary spectral region, opening possibilities for ultrafast ghost imaging at new wavelengths. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement