Patent ID: 8120765

Claim:
An observation device comprising: a light source unit for outputting light; an irradiation optical system for irradiating a subject with the light outputted from the light source unit; a detection optical system for guiding a beam generated upon the irradiation of the subject with the light by the irradiation optical system; a wavefront modulation unit for presenting a compensating phase pattern for compensating for an aberration of input light and a branching phase pattern for splitting the input light into first and second beams, inputting the beam guided by the detection optical system, phase-modulating the inputted beam according to the compensating phase pattern and branching phase pattern, and outputting the phase-modulated beam; a branching optical system for guiding the first and second beams outputted from the wavefront modulation unit while being split under action of the branching phase pattern into respective directions different from each other; a light detection unit for receiving the first beam guided and inputted therein by the branching optical system and detecting a power of thus received first beam; a wavefront detection unit for receiving the second beam guided and inputted therein by the branching optical system and detecting a wavefront of thus received second beam; and a control unit for adjusting the compensating phase pattern presented by the wavefront modulation unit according to the wavefront detected by the wavefront detection unit, and the branching phase pattern presented by the wavefront modulation unit according to a target value for the power ratio between the first and second beams outputted from the wavefront modulation unit while being split under action of the branching phase pattern.