Output Power Characteristics and CH4 Absorption of 3.39μm He-Ne Laser

Abstract

Optimum discharge and cavity parameters for output power, amplification of small signal, output power curve versus cavity tuning and CH4 absorption are investigated experimentally for the 3.39μm He-Ne laser under various conditions.
Dependence of output power on discharge current, pressure, tube diameter and mirror transmittance is shown graphically. Output power curves versus cavity tuning shows a Lamb dip in a pressure rang lower than 1 torr and an inverted Lamb dip with a CH4 absorption cell in a cavity. Height, width and profile of the inverted Lamb dip are examined. Absorption coefficient of CH₄ at room temperature is also measured.