The influence of the mode structure on the quantum theory of the laser

Muhammad Suhail Zubairy, Surendra Singh

Yu-Xin Xiao, Wentao Zhang

Based on scalar optical theory, the fundamental mode Gaussian laser standing wave model is built with Fresnel straight edge diffraction effect in the process of laser-focused Cr atoms. By numerical analysis and 3-D simulation on optical potential, characteristics in the laser standing wave are described under the influence of the distances from diffraction edge to mirror and laser medial axis to substrate surface, respectively. The results show that diffractive degree of the laser field will be changed for the substrate placement, and the structure of optical potential will be achieved optimal when the distance from diffraction edge to mirror equals 0.51 cm.

Deshui Yu, Jingbiao Chen

We investigate the influence of atomic transit time $\ensuremath{\tau}$ on the laser linewidth by the quantum Langevin approach. With comparing the bandwidths of cavity mode $\ensuremath{\kappa}$, atomic polarization ${\ensuremath{\gamma}}_{ab}$, and atomic transit broadening ${\ensuremath{\tau}}^{\ensuremath{-}1}$, we study the laser linewidth in different limits. We also discuss the spectrum of fluctuations of output field and the influence of pumping statistics on the output field.The influence of atomic transit time $\ensuremath{\tau}$ on laser field has not been carefully discussed before, to our knowledge. In particular, a laser operating in the region of ${\ensuremath{\gamma}}_{ab}⪡{\ensuremath{\tau}}^{\ensuremath{-}1}⪡\ensuremath{\kappa}∕2$ appears not to have been analyzed in previous laser theories. Our work could be a useful complementarity to laser theory. It is also an important theoretical foundation for the recently proposed active optical atomic clock based on bad-cavity laser mechanism.

A. P. Kazantsev

Daniel F. Walls, Gerard J Milburn

Jerry Yeung, Anirban Sarkar, Markus Pollnau

Rare-earth-doped solid-state lasers utilize distributed-feedback (DFB) resonators to generate ultra-narrow-linewidth emission down to a few kHz. The longitudinal modes of a single Fabry-Pérot and a DFB resonator are influenced by the structure, the optical excitation configuration, and external feedback, as has been observed experimentally. Here we investigate the influence of bi-directional launching of light and external feedback on the longitudinal modes of single Fabry-Pérot, double Fabry-Pérot, and DFB resonators. These results can be exploited for the technological advancement of DFB lasers.