Photon trains and lasing : The periodically pumped quantum dot
  We propose to pump semiconductor quantum dots with surface acoustic waves which deliver an alternating periodic sequence of electrons and holes. In combination with a good optical cavity such regular pumping could entail anti-bunching and sub-Poissonian photon statistics. In the bad-cavity limit a train of equally spaced photons would arise. 
C. Wiele, F. Haake, C. Rocke, A. Wixforth