- Excimer lasers operate at UV Laser wavelengths of 193nm, 248nm, 308nm and 351nm. Pulse duration is on the order of 20ns with average power in the 10’s of Watts to a few hundred Watts. The beam is somewhat unconventional in that is not round but 1cm x 2.5cm. As such, mask imaging is used to project the beam onto the workpiece. This is ideal for complex shapes and high density features. Feature sizes down to about 5 microns is possible. Material removal is through photo-ablation which results in very clean laser micromachining.
- Diode-Pumped-Solid-Sate Laser (DPSS Laser). Laser diodes are used to optically pump a laser crystal, typically Nd:Yag or Nd:YLF. Typical laser parameters are 10kHz-100kHz pulse repetition rate, 5-30ns pulse duration with average powers in 2-70 Watts. The fundamental wavelength of a DPSS Laser is 1,064nm. Non-linear crystals are used to convert the wavelength to 532nm in the visible or 355nm in the UV. The 355nm UV Laser is generally the laser of choice for Laser Micromachining.
- Ultrafast Laser. Lasers with a pulse duration of less than 1 ns are considered ultrafast or sometimes referred to as ultrashort pulse laser. They exhibit a unique coupling mechanism whereby the peak power is so great, the material goes from solid directly to vapor (sublimation) with virtually no heat effect. Photomachining offers laser micromachining systems with either a picosecond laser (10-12 Seconds) or a femtosecond laser (10-15 Seconds).