Patent ID: 9392944
Filing Date: 2016-07-19
CPC Classification: A61B,G01N,H01S

Claim Text:
1. A laser source unit that sequentially emits a plurality of pulse laser beams in a predetermined wavelength sequence including at least two different wavelengths, the laser source unit comprising: a laser rod; an excitation light source that irradiates the laser rod with excitation light; an optical resonator including a pair of mirrors facing each other with the laser rod interposed therebetween; a Q switch which is inserted into the optical resonator; a birefringent filter which is inserted into the optical resonator and changes an oscillation wavelength of the optical resonator in association with rotational displacement of the birefringent filter; a rotation control unit that rotates the birefringent filter at a predetermined rotation speed depending on the number of wavelengths included in the wavelength sequence; and an emission control unit that irradiates the laser rod with excitation light from the excitation light source and then turns on the Q switch, at a timing when a rotational displacement angle of the birefringent filter is set to a position where the optical resonator oscillates at the wavelength of the pulse laser beam to be emitted, to cause the pulse laser beam to be emitted, wherein the rotation control unit sets the predetermined rotation speed of the birefringent filter, wherein the laser source unit emits the pulse laser beam in one free spectral range based on the predetermined rotation speed set by the rotation control unit, the predetermined rotation speed is determined on the basis of changes in an oscillation wavelength for the rotational displacement angle of the birefringent filter, the number of wavelengths included in the wavelength sequence, and the number of times of emission of the pulse laser beam per unit time, and the free spectral range is repeated a number of times during a single rotation.