We know that laser energy can be delivered in two modes – continuous wave mode (CW) and pulsed mode. In pulsed mode, the laser energy is delivered in the form of small pulse duration. Continuous technological advances have made it possible to shorten the pulse duration from microsecond laser, nanosecond laser, picosecond laser to now femtosecond laser and attosecond laser pulse duration.
Generally, subpicosecond (about 1-20ps) and shorter duration laser pulses have been recognized as ultrashort lasers. What is special about these ultrashort laser pulses? What kind of advantages these ultrashort laser pulses can offer otherwise not possible in comparatively longer duration pulses? Why are they swiftly replacing the traditional materials processing in various industries?
Ultrashort laser can focus the energy in a very short interval of time generating a high peak power, not possible in CW lasers. This new kind of intense laser beam generates new possibilities in different industrial sectors.
Ultrashort lasers do not generate heat affected zone (HAZ), a big problem in laser based materials processing and micromachining that arises due to thermal effects. Due to no HAZ formation, ultrashort lasers are popular for efficient materials removal.
Ultrashort lasers allow single step fabrication of 3D photonic device structures giving big relief from traditional thin film based multistep process.
Ultrashort lasers made it possible the microprocessing of flexible geometries and high standard edges on brittle materials like glass, quartz and ceramics.