Today, laser systems serve an array of applications in several industries. Discussed below are some of the widely used industrial laser systems.
- Arc Lamp: Also known as flash lamp, this system produces a relatively long pulse (in milliseconds). This makes it useful as optical pump sources for solid state lasers. However, it is unsuitable to use with an optical fiber for delivery to a lightweight, portable tool due to the broad distribution of light.
- CO2 Laser: Two types of CO2 lasers are in use:
- Continuous Wave (CW) lasers, which generate continuous light, are used for cutting, engraving, marking, and welding.
- Transversely-Excited Atmospheric pressure pulsed lasers (TEA), are generally operate in the infrared light spectrum at 10.6 and 9.4 micrometers. TEA lasers have very high repetition rates, and are used extensively for marking discrete electronic components.
- Diode Laser: These lasers create laser light directly from electricity with the help of semiconductor diodes. They are the most efficient in converting electrical input power to laser output power. They have coating removal characteristics similar to flash lamps. Diode lasers are designed either as CW or long pulse lasers.
- Neodymium-doped Yttrium Aluminum Garnet (Nd: YAG) Laser: This is a solid state laser, and is the most frequently used system for laser ablation. It is commercially available in several configurations with varying characteristics. Nd: YAG lasers generate a near-infrared wavelength (1.064 um) that works well for optical fiber delivery. The differences are in the pulse width and pumping mechanism.
- Flash Lamp Pumped, Q-Switched Nd: YAG Laser: This provides the shortest pulses among all laser systems (10ns). These short pulses make for efficient stripping, but it is difficult to deliver them through optical fibers at high average power, as peak power levels often exceed fiber capacity. Additionally, these lasers use flash lamps and pulsed high-voltage supplies with relatively short operating lives (hundreds of hours), that imposes reliability and maintenance constraints.
- Arc-Lamp Pumped, Q-Switched Nd: YAG Laser: These provide a somewhat longer (100ns) pulse than flash lamp-pumped lasers that is effective for stripping. However, these lasers also suffer the efficiency and reliability problems, but to a lesser extent.
- Diode-Pumped Q-Switched Nd: YAG Laser: Here the Nd: YAG material is pumped with the help of diode laser. They have the same pulse characteristics as the arc-lamp pumped laser, but with greater electrical efficiency and reliability. Hence, cooling requirements are greatly reduced. The diode lifetime is specified at 10,000 hours, significantly improving the reliability of this laser system. It is highly preferred for coating removal applications.
- Femto-Second Lasers: These provide extremely short pulses with consistently high peak power. They produce virtually no substrate heating and are used in micro-ablation applications. However, their cost, reliability, and issues with beam delivery make them impractical for certain applications.
- Fiber Lasers: CW (continuous wave) and Q-switched are the two varieties of fiber lasers.
- CW fiber lasers offer optimum power levels up to 50 Watts and are presently the leaders in high average power. Despite their power levels, the challenges are similar to that posed by CW CO2 lasers.
- Q-switched fiber lasers’ performance is very similar to diode-pumped Q-switched Nd: YAG lasers, with a much better reliability. There is no need for a large power supply, water cooling, or RF Driver. There are no consumables, and the lifetimes of these lasers are extremely long. Q-switched fiber lasers have a much smaller footprint than any other laser system, and are offered in a wide range of power levels.
With such an extensive range of options available, you can choose a suitable laser marking machine to meet your marking needs.
