Hyperspectrally Compressed Ultrafast Photography

The spatial, temporal, and spectral information in optical imaging play a crucial role in exploring the unknown world and unencrypting natural mysteries. However, the existing optical imaging techniques can only acquire the spatiotemporal or spatiospectral information of the object with the single-shot method. Here, we develop a hyperspectrally compressed ultrafast photography (HCUP) that can simultaneously record the spatial, temporal, and spectral information of the object. In our HCUP, the spatial resolution is $1.26\mathrm{lp}/\mathrm{mm}$ in the horizontal direction and $1.41\mathrm{lp}/\mathrm{mm}$ in the vertical direction, the temporal frame interval is 2 ps, and the spectral frame interval is 1.72 nm. Moreover, HCUP operates with receive-only and single-shot modes, and therefore it overcomes the technical limitation of active illumination and can measure the nonrepetitive or irreversible transient events. Using our HCUP, we successfully measure the spatiotemporal-spatiospectral intensity evolution of the chirped picosecond laser pulse and the photoluminescence dynamics. This Letter extends the optical imaging from three- to four-dimensional information, which has an important scientific significance in both fundamental research and applied science.

Figure 1

HCUP principle and configuration. (a) HCUP principle. $I(x,y,t,\lambda )$ original scene: measurement image $E(x^{\prime },y^{\prime })$, encoding operator $C$, spectral operator $S$, temporal operator $T$, multiplexed operator $M$. (b) HCUP system configuration.

Figure 2

Characterizing spatial resolution. (a) Experimental setup: (1–8) mirror, (9) and (10) beam splitter, (11) resolution test chart. (b) Reconstructed images of elements 2–4 in group 0 of test resolution target. (c),(d) Measured static image of test resolution target from external CCD and selected dynamic image from (b). (e),(f) Integrated intensities for horizontal and vertical lines in (d).

Figure 3

Imaging chirped picosecond laser pulse. (a) Experimental design. (b) Reconstructed images. (c),(d) Time-resolved spectroscopies calculated from (b) and directly measured by the streak camera, respectively. (e),(f) Laser spectra and pulse durations calculated from (c) (red lines) and (d) (blue lines).

Figure 4

Capturing photoluminescence dynamics. (a) Experimental arrangement. (b) Reconstructed images. (c),(d) Time-resolved spectroscopies calculated from (b) and directly measured by a streak camera, respectively. (e),(f) Fluorescence spectra and luminescence dynamics calculated from (c) (red lines) and (d) (blue lines).