This paper is intended to outline the current thinking regarding the process involved in depilation by pulsed ruby laser. The key laser parameters of wavelength, pulse duration, energy density, spot size and spatial profile will be discussed together with their impact on the outcome of the procedure. A parallel series of clinical trials have been carried out in a number of centers on both medical complications of hair growth and the cosmetic use of the technology. The results of these trials detail the efficacy of the treatment as well as the incidence of side-effects or complications.
Experiences in the use of a new design of flashlamp pumped dye laser operating at 585 nm are outlined. This includes explanation of laser parameters and early clinical results on a cross section of medical conditions. In excess of 1500 patients have been treated with a good therapeutic outcome.
When used in continuous wave (cw) mode the CO<SUB>2</SUB> laser is an effective tool for vaporizing unwanted tissue, however, there is the possibility of the accumulation of thermal energy in the good tissue close to the point of treatment. If this thermal energy is high then post operative pain and scarring could result. This is avoidable by delivering the energy in short pulses with the gap between those pulses being greater than the thermal relaxation time of the tissue (which can vary according to tissue type that is typically 0.5 to 3.0 ms). Simply chopping the laser beam rapidly would produce the desired thermal effect but would waste a large percentage of the laser energy and greatly extend the treatment time since the average output power of the laser is compromised. The ideal scenario is where the laser power is enhanced for the on period producing an average power similar to that obtained in cw mode.
The Carbon Dioxide laser has been a proven medical tool for over ten years with established applications in Gynaecology, Dermatology, E.N.T. and Oral surgery. Over the years, major technological advances have been made leading to a number of products available on the market. These technological advances include: sealed tube technology, close 1oop cooling, superpulsed operation. However, despite several indications to the contrary, a flexible fibre delivery system for this wavelength has not emerged. This limits the application of the carbon dioxide laser in medicine to those where direct line of sight access to the treatment area is possible. This investigation of the interaction of CO laser light with tissue was motivated mainly by the possibility of fibre delivery of the 5 micron wavelength. If the CO laser has a similar tissue interaction to 2' then there could be a major market for such medical laser systems. The fibre delivery would open new potential treatments in fields such as angiopasty, laserthermia and other procedures possible only by fibre delivery.