Micromachining of glassy carbon using a Yb-based master oscillator power amplifier nanosecond fiber laser

Laser machining of glassy carbon was experimentally investigated using a 1065 nm wavelength Yb-based master oscillator power amplifier fiber laser source. Ablation characteristics were determined for SIGRADUR G glassy carbon samples using laser fluence of less than 3J/cm². The ablation threshold was found to be 0.31J/cm² for incident pulse repetition rates of 250 and 500 kHz. Glassy carbon exhibited excellent machining characteristics with features of clearly defined edges and smooth surfaces. The ablation rate varied linearly with fluence over the range 0.31-1.3J/cm². High-quality glassy carbon microstructures were created with optimum laser parameters.