Patent ID: 6992820

Claim:
A fluorescence microscope that is switchable between Koehler illumination mode and total-reflection fluorescence illumination mode, comprising: a laser light source; an optical fiber having an entrance end and an exit end for conducting light from the laser light source; an irradiating optical system which irradiates a sample with light emanating from the optical fiber, the irradiating optical system comprising a first collecting optical system disposed on a side of the sample and a second collecting optical system disposed on a side of the optical fiber, the second collecting optical system collecting the light emanating from the optical fiber on a back focal point of the first collecting optical system or a vicinity thereof; and a light projecting tube that houses the irradiating optical system; an adapter section that connects the exit end of the optical fiber with the light projecting tube; and a switching mechanism constructed and arranged at the adapter section to switch between the Koehler illumination mode and the total-reflection fluorescence illumination mode, the switching mechanism comprising a moving mechanism which moves the optical fiber in a plane perpendicular to an optical axis of the irradiating optical system to thereby move the exit end of the optical fiber from a first position on the optical axis of the irradiating optical system where the Koehler illumination mode is achieved to a second position separated from the optical axis of the irradiating optical system where the total-reflection fluorescence illumination mode is achieved with total reflection being caused in a vicinity of the sample.