Time-Integrated Images of Linear Striated Filamentary Laser Sparks

摘要

The dependence of time-integrated photographic and linear diode array images of linear striated filamentary laser sparks on gas pressure and laser energy is described. For sparks in air, it was found that the pressure regime 100-300 Torr produces images of minimum diameter (about 150 mu m) and maximum sharpness. Diode array images exhibit longitudinal and transverse luminosity profiles which differ from photographic images due to different spectral sensitivities. These data are of value in using the linear laser spark as an imaging probe of inhomogeneous gases such as turbulent reacting flows and diffusion flames.