A medical laser apparatus comprises: a solid laser oscillating source which emits a beam of a wavelength .lamda.1 in an infrared region of approx. 1040 nm to approx. 1080 nm; a first fiber-based Raman shifter including a first Raman fiber which generates, when receives the .lamda.1-beam from the laser oscillating source, a first-order Stokes beam of a wavelength .lamda.2 different from the wavelength .lamda.1 by stimulated Raman scattering, the first Raman fiber being formed with a pair of fiber Bragg gratings which forms a resonator for the .lamda.2-beam; a first nonlinear crystal which wavelength-converts the .lamda.2-beam outputted from the first Raman wavelength shifter to a second harmonic beam of a wavelength .lamda.2' in an orange region of approx. 580 nm to approx. 600 nm; and a light guiding optical system which guides the .lamda.2'-beam to a treatment part.
A medical laser apparatus suitable for medical treatment, which is capable of obtaining a plurality of visible laser beams each having a different wavelength, but which has an inexpensive structure.A medical laser apparatus capable of selectively irradiating a plurality of visible laser beams each having a different wavelength onto an affected part, comprises: a fiber laser source unit including an excitation light source, a plurality of fiber lasers for oscillating, by means of excitation light from the excitation light source, a plurality of infrared fundamental beams each having a different wavelength and a first optical switch having an input portion and a plurality of output portions for selectively switching a transmission path of the excitation light from the excitation light source to one of the fiber lasers, the fiber laser source unit being capable of selectively oscillating the fundamental beams; and a plurality of wavelength conversion elements for wavelength-converting the fundamental beams, from the fiber laser source unit, to a plurality of visible second harmonic beams.
