Applications

Femtosecond lasers offer exceptional control over laser–tissue interaction and, subsequently, minimal thermal damage on the irradiated tissue compared to picosecond, nanosecond, or continuous wave (CW) lasers. Thus, they can be applied as treating and surgical tools in such medical disciplines as ophthalmology, dermatology, dentistry, intestinal surgery, and others.

The analysis of laser–tissue interaction using ultrashort pulsed lasers demonstrated that new generation solid-state femtosecond lasers with harmonic generators for UV radiation could be a progressive change in corrective surgery of surface organs requiring very precise ablation. For example, one of the most promising disciplines is ophthalmology. In particular, results by Danieliene et al. have shown corneal stromal ablation with femtosecond UV pulses in rabbits comparable with or superior to those obtained using argon fluoride excimer laser. A substantial advantage of the new-generation femtosecond lasers, PHAROS and CARBIDE, is the possibility of generating femtosecond light pulses in both the infrared and UV ranges, implying that a wide range of ophthalmic or dermatological procedures can be performed using a single laser source.

In some other cases, such as colon tissue resection, endoscopic procedures are required. Up to the recent development of hollow-core fibers, this has been hindered by the lack of suitable optical fibers for high peak power delivery. In a recent article by Shephard’s group, hollow-core fibers were successfully applied to deliver ultrashort pulses throughout the body, while the use of such pulses enabled a minimal thermally damaged region in the tissue and fine depth control of ablation. The study concluded that the combination of ultrashort pulses and hollow-core fiber delivery resent a viable route to novel minimally invasive surgical procedures.