Nonlasing Conditions Research Articles

Measurement of Collisional Relaxation Process for Argon Ion Laser Using the Change of Spontaneous Emission Intensities at Lasing and Non-lasing Conditions

Measurement of Collisional Relaxation Process for Argon Ion Laser Using the Change of Spontaneous Emission Intensities at Lasing and Non-lasing Conditions

Pulse shape and laser-energy extraction from e-beam-pumped KrF

In this paper, detailed comparisons are made between the numerical predictions of a comprehensive KrF kinetics/laser-model computer code and the experimental results from an e-beam-pumped KrF laser. The code and the experimental laser device are described. The inputs to the code are the measured temporally varying e-beam energy and current density, the laser mixture, the optical-cavity output coupling, and the optical gain length. Comparisons include laser output power, laser output pulse shape, and KrF* fluorescence from the laser-cavity sidelight under lasing and nonlasing conditions. Using our numerical model, we have generated a scaling map for the KrF* laser.

Study of the Vibrational Population Distribution of N2 in a CO2–N2–He Laser and Determination of the Vibrational Temperature

The sidelight emission from a CO2–N2–He laser was observed for different conditions of the discharge. The band intensity of the N2 second positive series showed a linear dependence with the current for any given mixture: this fact confirms an excitation mechanism of the C3πu state by electronic impact from the ground state. The same series has been registered for different mixture pressures, to determine the excitation and energy transfer mechanisms of the gases in the discharge. From the intensity of the sequence Δv=3 the population distribution among the N2C3πu vibrational levels has been calculated for different discharge currents. The vibrational temperature increased on passing from lasing to non-lasing conditions, for fixed mixtures and discharge currents.

Degradation characteristics of cw optically pumped AlxGa1−xAs heterostructure lasers

The characteristic formation of dark filamentary features during the rapid degradation mode of AlxGa1−xAs double-heterostructure lasers has been observed in material with no contacts, with or without a p-n junction, and in minimal-strain mounting configurations. The degradation was observed in optically pumped cw lasing and nonlasing conditions with active region temperatures near and above room temperature.

Role of optical flux and of current density in gradual degradation of GaAs injection lasers

A GaAs dual-diode laser structure was used to give electrical control of the laser threshold and so permit separate study of the effect of optical flux on gradual degradation. At a given current density, degradation occurs under nonlasing conditions at about the same rate as under normal lasing conditions. The degradation rate is a superlinear function of current density. Degradation is an erratic process in which the rate varies sporadically during operation.