Quantum noise of lasers with multi-photon absorption and reduce pump noise

Nitu Sahu, Binod Kumar Choudhary, Dilip Kumar Giri

: In this paper, difference squeezing in the degenerate three-photon absorption six-wave interaction process is examined. The difference squeezing in fields between the pump and Stokes modes can be converted to normal squeezing in the signal mode, and vice versa. It is demonstrated that in the pump mode, amplitude-cubed squeezing is directly turned into normal squeezing in the signal mode. The squeezing in the stimulated interaction, which reduces the depth of classicality of the field amplitude, is seen to be larger than the corresponding squeezing in the spontaneous interaction, despite having the same number of pump photons. Difference squeezing is observable only in certain domain values of pump photons. It is deduced that the multi-photon absorption nonlinear optical approach is the best way to generate optimal squeezed laser light in any optical system.

Helmut Ritsch, P. Zoller

M. Lax, W. H. Louisell

Jing Xia

The instantaneous effect of and dynamics of Er-doped fiber laser is studied.The transient effect mechanism of Er-doped fiber laser under the pumping disturbance is a kind of forced vibration behavior.The paper gives the photon population density perturbations with time in Er-doped fiber laser and the fluctuation functions of photon population density are solved at the first order approximation When pumping perturbations have white noise characteristics,the dynamical characteristic of the laser is increased with pumping perturbations;the resonance absorption extent is widened,but it makes the stability of the laser reduced at the same time.This paper elaborates that the value of photon population density will increase along with the increase of the ion density and the photon life in the resonance phenomenon,and the unstability of the laser will be strong,but the opposite value will be diminished.

Ulrike Herzog

Abstract The intensity noise spectrum is investigated quantum‐mechanically for incident coherent light passing through a resonator which is filled with a k‐photon‐absorber. For k⩽ 2 the noise of the outgoing light is reduced below the shot noise level the reduction being maximal for frequencies that are small in comparison to the cavity bandwidth. It turns out that the highest possible value of this low‐frequency noise reduction is obtained when the resonator losses due to transmission through the outcoupling mirror are 2k – 1 times as large as the k‐photon absorption losses. In this case the noise at zero frequency is reduced with respect to the shot noise level by a factor of k/(2k – 1).

J. P. Woerdman, Martin P. van Exter, N. J. van Druten