Time-to-frequency Fourier transformation with photon echoes.

We propose to use photon echoes in rare-earth-doped crystals to implement the Fourier-transform chirp algorithm. The process is considered for application to spectral analysis of fast radio-frequency signals. Compared with surface acoustic wave devices, the proposed scheme gives access to the larger bandwidths of rare-earth-doped crystals and greater flexibility. An experimental demonstration of the proposed process is reported.