On-demand acoustic shaping of Mössbauer γ-ray photons

We propose a technique that makes it possible to transform the intensity of a quasimonochromatic singlephoton wave packet, emitted by a radioactive M & ouml;ssbauer gamma -ray source, into a sequence of short bursts with an arbitrary number of bursts, including a single burst. In addition, the technique allows one to individually and independently control, on demand, the moments of the burst appearance, as well as the peak intensity, duration, and shape of each burst in the sequence. The technique is based on the transmission of M & ouml;ssbauer (recoilless) photons through a resonantly absorbing medium, which is rapidly displaced at some moments of time relative to the source (or vice versa) along the photon propagation direction at a distance less than the photon wavelength, and returned to its original position. The burst duration can be comparable to the duration of the single-photon pulses that are produced by synchrotrons but have the controlled spectral-temporal characteristics. We show that the proposed technique can be implemented on the basis of currently available equipment with the use of 14.4-keV recoilless photons, emitted by a 57Co source and a 57Fe absorber, which opens up prospects for its applications in M & ouml;ssbauer spectroscopy and x-ray quantum optics.