Two-peak passage time distributions in transient CO2 lasers near threshold

We investigate two-peak passage-time statistical distributions in a Q-Switched CO2 laser using the excitation current as the control parameter. This two-peak statistics is due to the Population-inversion noise when the initial laser state is set close to threshold. Such a phenomenon has been experimentally observed in a class-B laser when the passage time is shorter than the relaxation time of the population inversion. The time separation of the two peaks can be quantitatively related to the laser net pin.