Medical laser apparatus for delivering high power infrared light

A medical laser apparatus comprising:

• a fluoride-based optical fiber having a core and a cladding;
• an erbium YAG laser coupled to said optical fiber, said erbium YAG laser producing invisible infrared light at a wavelength of about 3 microns, said infrared light propagating in said core at a power density of at least 4 kilowatts per square centimeter;
• and
• a polyimide buffer surrounding said optical fiber.

A medical laser apparatus for delivering multiple wavelengths of optical energy to a treatment site, comprising:

• a waveguide comprising a fluoride-based guiding structure which transmits invisible infrared light at a first wavelength efficacious for cutting tissue and light at a second wavelength efficacious for coagulating tissue, said guiding structure transmitting light at a power density of at least about 4 kilowatts per square centimeter, said guiding structure consisting of a core having a refractive index and at least one cladding having a refractive index lower than that of said core, said wave guide additionally comprising a protective structure comprising a material which is substantially impermeable to moisture and has a moisture resistance significantly higher than that of said guiding structure, said protective structure surrounding said guiding structure and juxtaposed therewith such that said protective structure receives a portion of said light having said power density, said portion of said light received by said protective structure being in the form of leaky modes, said protective structure being flexible and having relatively high resistance to bending compared to said guiding structure to protect said guiding structure against breakage, said protective structure additionally having a sufficiently high transmittance to said light, such that the energy of said light in said leaky modes is dissipated from said protective structure without damaging said waveguide;
• a first laser, coupled to said waveguide, for providing light at said first wavelength at a dosage sufficient to cut tissue;
• and
• a second laser, coupled to said waveguide, for providing light at said second wavelength at a dosage sufficient to coagulate tissue.