Laser resonator design with improved signal-to-noise level (S/N) at the output of a single-mode fiber-coupled multi-wavelength laser providing illumination for a laser scanning microscope

摘要

A single-mode fiber-coupled multi-wavelength laser, wherein, for suppressing higher order transverse modes of the laser cavity than TEM. sub.oo of at least one laser emission wavelength or for increasing the beam waist diameters of the transverse laser cavity modes or for increasing the signal-to-noise level of the output of the laser at least at one emission wavelength, one or more of the following is selected: P Pa) at least one resonator mirror movable along the resonator axis in order to vary the resonator length;PPb) at least one resonator mirror tiltable until a surface normal thereof encloses an angle (0. noteq.0) with the resonator axis;PP c) at least one resonator mirror being replaced by another concave mirror with different curvature radius; PPd) at least one resonator mirror being replaced by a flat mirror; andPPe) at least one mirror holder allowing the interchangeable use of several mirrors with different curvature radii.