| In many laser processing applications ultrashort laser pulses have certain advantages, relative to picosecond and longer laser pulses. Several research groups have demonstrated the utility of femtosecond laser pulses in precision micro-machining and micro-structuring of a wide variety of materials including metals, ceramics, composites, glasses; and polymers. Unfortunately, the advantages gained in machining precision, repeatability, and reduced Heat Affected Zone (HAZ) generally come at the expense of greater laser system complexity and cost. Here, we present research conducted on femtosecond laser machining at the Laser Plasma Laboratory (LPL). This research can be split into three parts. The first compares nanosecond and femtosecond laser pulse deep hole drilling in transparent media. The second section investigates specific issues involved in femtosecond laser materials processing, and provides evidence of a new physical mechanism: self-focusing in the atmosphere and laser/plasma interactions. The last section describes recent laser development work, in which we design and construct a modified Ti: Sapphire femtosecond laser oscillator capable of producing sub-50 femtosecond laser pulses with sufficient laser intensity for a wide variety of micromachining applications. |
