Effect of Flow Velocity on Generation Condition of Diode Laser-sustained Plasma using Argon

Abstract

Laser-sustained plasma (LSP) is a promising method for generating atmospheric pressure plasmas. Although diode lasers are a highly efficient, compact, and low-cost light source for this method, previous studies have only reported LSP generation under gas-filled conditions. In this study, LSP generation under argon gas flow conditions using a 4-kW-class diode laser was investigated, and its various characteristics were examined. The minimum laser power required for LSP generation remained constant at 2,900 W for flow velocities between 0 and 220 mm/s at 2.0 MPa. The LSP temperature increased from 12,000 K to 14,000 K as flow velocity increased. The length of the LSP did not change with flow velocity, but the LSP position decreased from 2.0 mm to 1.3 mm as the flow velocity increased.