Contribution to the theory of single-mode laser modulation II. Conduction modulation

L. Aubrecht

Sun-Hyun Youn, Jai-Hyung Lee, Joon-Sung Chang

Electromagnetic fields of the vacuum mode near a conducting mirror are modified with respect to those in free space, with their amplitudes having a sinusoidal spatial dependence from the mirror. Therefore if we combine this spatially amplitude-modulated vacuum field mode and intense coherent light with a beam splitter, we may detect this fluctuation of the vacuum mode in a homodyne detection scheme. It will give a new method to produce squeezed states of light with a single mirror placed close to an unused port of a beam splitter. We show that the amplitude fluctuation of the combined light can be reduced by a factor of 2 below that of the coherent light. We also discuss the limitations due to the finite line width of the laser and the effective absorption length of the photodiodes.

R. N. Shakhmuratov, A. R. Kessel

P. Titterton

A rigorous quantum-mechanical treatment of the internally phase-modulated laser is performed in terms of traveling-wave modes of the quantized electromagnetic field. A detailed treatment of the modulation process is consistent not only with the phase-locked and FM behavior of the laser, but also describes the external (to the laser cavity) frequency shifting of phase-locked light and single-frequency ("super-mode") operation of the FM laser.

Kōichi Shimoda

Yong He, Eli Barkai

We consider the theory of single photon on demand from a two level atom or molecule source. Using optical Bloch equations and the generating function formalism we investigate three approaches to single photon control: (i) the square laser pulse; (ii) the square modulation of absorption frequency; and (iii) the rapid adiabatic following approach investigated in the experiments of Brunel et al., Phys. Rev. Lett., 1999, 83, 2722. We discuss the conditions for obtaining the maximum of the probability of emission of a single photon and a pair of photons, under the constrains of finite field strength and finite interaction time with excitation field. We obtain analytical expression for the probability of emitting zero, one, and two photons for the square pulse, and discuss semi-classical and strongly quantum limiting cases. Numerical results obtained from the generating function formalism are compared with experimental results showing that the two level system approach is suitable for the description of cryogenic temperature single molecules, and that experiments were conducted very close to the optimal conditions.