| 摘要 |
PROBLEM TO BE SOLVED: To provide an illumination optical system, microscope device and illumination method that enable an adjustment of an interference fringe to be formed on a sample.SOLUTION: The present invention relates to an illumination optical system that comprises: a branch unit that branches light from a light source into a plurality of light fluxes; a phase modulation device 21 that has a first area upon which a first light flux of the plurality of light fluxes is incident and a second area upon which a second light flux of the plurality of light fluxes is incident, and can change each of a refractive index distribution of the first area and a refractive index distribution of the second area; a first optical system 24 that causes the first light flux and the second light flux to be interfered with each other to illuminate an illumination area with the interference fringe; and a second optical system that converges the first light flux from the phase modulation device to a rear-side focal plane of the first light flux, and converges the second light flux from the phase modulation device to a position different from a position having the first flux converged in the rear-side focal plane. The position of the first light flux of the rear-side focal plane is adjusted by a change in the refractive index distribution of the first area, and the position of the second light flux of the rear-side focal plane is adjusted by a change in the refractive index distribution of the second area. |
