Detuning Effect Between the Cavity Resonance and Atomic Transition Frequencies on Noise Flux Profiles of Class-C Lasers

The class-C lasers are well recognized to have very narrow atomic transition bandwidths. Therefore, a minor mismatch between the cavity resonance and atomic transition frequencies (CAF) is normally led to the large modifications in the gain and noise profiles. The motion of class-C lasers is described by the three variables of cavity electric field, atomic population inversion, and dipole moment of atoms that are coupled to each other by the optical Maxwell-Bloch equations. The fluctuating features of these three variables are completely elaborated by solving their equations of motion in the presence of the cavity Langevin force. The results peculiarly indicate that the noise profile of the cavity electric field exactly mimics the amplification profile of an input signal by the laser in both below and above threshold states. The both gain and noise profiles simultaneously tend to infinity at the normalized pumping rates and CAF mismatches determined by the laser stability theory. The noise flux profiles are finally confirmed by illustrating the flux conservation.