Time-domain Fresnel-to-Fraunhofer diffraction with photon echoes.

A photon echo experiment in Tm(3+):YAG is reported that shows, for the first time to the authors' knowledge, the time-domain equivalent of the transition from near- to far-field diffraction, including Talbot self-imaging effects. The experiment demonstrates the huge dispersion capability of photon echoes and opens the way to further exploration of space-time duality.

Fresnel diffraction on the edge of causality.

Taking advantage of the slow optical response of low-temperature rare earth ion-doped crystal, we explore the similarity between causality and Fresnel diffraction by a straight edge. We relate these features to spectral resolution and selectivity. The concept is illustrated with experimental data.

Diode laser extended cavity for broad-range fast ramping.

A novel design for an extended-cavity diode laser is presented. The cavity contains an electro-optic prism for synchronous tuning of the cavity length and the grating's incident angle. A simple analysis of the cavity is presented.

Measuring time-domain optical response functions with an optimized sampling rate.

We propose a time-domain interferometry method that circumvents the usual sampling rate condition. It was devised for the retrieval of fast optical response functions in low-repetition-rate experiments. Its potential temporal dynamic range matches the spectral resolution and bandwidth requirements of the arbitrarily shaped spectral filters that are engraved in amorphous spectral hole-burning materials.

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.