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Unique Characteristics of Ultrafast Pulsed Lasers
The truly unique and promising characteristics of the ultrafast pulsed lasers have opened up new opportunities for processing special materials. It means the materials that use ultrashort pulse widths and extremely high peak intensities. Currently, ultrafast pulsed lasers are increasingly being utilized for both fundamental research and practical applications. The laser manufacturing market is currently expected to exceed $17 billion in value by 2020 and grow at a rate of about 6 percent for the next five years. This fast, steady increase is due to wide use in various parts of the science world, including aerospace, automotive, and biomedical.
Conventional fiber laser techniques that commonly use nanosecond and longer pulses are hopelessly outdated: they are being replaced by materials processing with ultrafast lasers. The aforementioned fiber lasers can be used for working with such materials that require special conditions where the thermal influence must be minimized, for example, during the drilling of metals and cutting wafers, polymeric stents, and display glass. The companies that manufacture lasers produce more and more ultrafast lasers (also known as ultra-short pulse): picosecond and femtosecond fiber lasers. These ultrafast laser systems have a temporal pulse (the amount of time the laser light is in contact with the material) that is three to six orders of magnitude shorter than conventional fiber lasers.
Picosecond and Femtosecond Fiber Lasers
- Picosecond fiber lasers emit optical pulses between 1 ps and some tens of picoseconds.
- A femtosecond fiber laser emits optical pulses with a duration well below 1 ps.
The quality comparison between picosecond and femtosecond lasers is material-dependent. It can be very subtle or very apparent in different instances. The femtosecond ultrashort pulsed laser is a clear choice when the absolute best quality is needed, but it should be noted, the picosecond ultrafast fiber lasers tend to machine faster.
Ultrafast Laser Processing Applications
Ultrafast laser processing has fundamentally changed the way of materials microprocessing with fiber lasers. Ultrafast fiber laser has become a micromachining tool for various materials, including metals, semiconductors, ceramics, glass, crystals, polymers, and even soft materials like biotissues. In addition to this, these scientific ultrafast laser systems have also been employed for several practical and industrial applications. These fiber lasers are now also used in the electronics industry for scribing, patterning, and texturing of glass and semiconductors.
Advantages in Precision and Heat-sensitive Material Processing
As devices become smaller and more complex, laser machining will have to continue to push the edges of performance. Now we already know that the ultrashort pulsed lasers can produce nanoscale holes. Fiber-optic laser systems can deliver a very precise concentration of light over such a short duration. This feature helps to avoid heat damage to the surrounding material and makes such ultrafast lasers irreplaceable for machining heat-sensitive biomaterials.