Laser-Tissue Interaction
Femtosecond lasers offer exceptional control over laser-tissue interaction, resulting in minimal thermal damage to the irradiated tissue compared to picosecond, nanosecond, or continuous wave (CW) lasers. Consequently, they can be applied as treatment and surgical tools in various medical disciplines such 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 bring significant advancements in corrective surgery of surface organs requiring very precise ablation. For example, one of the most promising fields is ophthalmology. In particular, results by Danieliene et al. have shown that corneal stromal ablation with femtosecond UV pulses in rabbits is comparable to or superior to those obtained using argon fluoride excimer lasers. A substantial advantage of the new-generation femtosecond lasers, PHAROS and CARBIDE, is their ability to generate femtosecond light pulses in both the infrared and UV ranges, allowing a wide range of ophthalmic or dermatological procedures to be performed using a single laser source.
In other cases, such as colon tissue resection, endoscopic procedures are required. Until the recent development of hollow-core fibers, this was 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. The use of such pulses enabled minimal thermally damaged to the tissue and fine depth control of ablation. The study concluded that the combination of ultrashort pulses and hollow-core fiber delivery presents a viable route to novel minimally invasive surgical procedures.
