Serna Galán, JulioEncinas Sanz, FernandoMartínez Herrero, María RosarioMejías Arias, Pedro Miguel2023-06-202023-06-202000-010306-891910.1023/A:1007033113828https://hdl.handle.net/20.500.14352/58588© Kluwer Academic Publishers. The research work leading to this paper has been supported by the Comisión Interministerial de Ciencia y Tecnología of Spain, under Project PB97-0295, within the framework of EU-1269 Eureka Project.The evolution of the intensity profile of TEA CO_2 laser pulses along the pulse length is investigated both analytically and experimentally. A simple scalar model of the pulse amplitude is introduced, which gives the loaded-cavity modes as a linear combination of bidimensional Hermite-Gauss functions. According to this model a number of equations are derived which link the time-varying spatial structure of the pulse to its time-resolved second-order intensity moments, namely, the beam width and the M^2 parameter.engjournal articlehttp://link.springer.com/article/10.1023%2FA%3A1007033113828http://link.springer.com/open access535Parametric CharacterizationOptical-SystemsBeam ParametersLightLawsÓptica (Física)2209.19 Óptica Física