Abstract: This microscope optical system comprises an objective lens that collimates light from an object, and an image formation lens (IL) that forms an image of light from the objective lens. The image formation lens (IL) comprises a first lens group (G1) having a cemented lens (CL11), a second lens group (G2) having positive refractive power, and a third lens group (G3) having negative refractive power, which are arranged in order from the object side, and satisfies the following conditional expression. 0.1<?en/f<0.2 where ?en is the pupil diameter of the objective lens, and f is the focal length of the image formation lens (IL).

Abstract: A microscope objective lens (OL) includes a first lens group (G1) and a second lens group (G2) arranged in order from the object side. The first lens group (G1) has positive refractive power and converts luminous flux from an object into convergent luminous flux. The second lens group (G2) has negative refractive power and converts the convergent luminous flux from the first lens group (G1) into parallel luminous flux. The microscope objective lens (OL) satisfies the following conditional expression: 14.0?NA×f 1.0<H1/HO Where NA is the numerical aperture of the microscope objective lens (OL); f is the focal distance of the microscope objective lens (OL); H1 is the maximum value of the height of marginal rays from an on-axis object point of the first lens group (G1); and HO is the height of marginal rays on the lens surface closest to the image side of the second lens group (G2).

Abstract: A structured illuminating apparatus includes a branching unit branching an exit light flux from a light source into at least two branched light fluxes, an illuminating optical system making the two branched light fluxes to be respectively collected at mutually different positions on a pupil plane of an objective lens and making the two branched light fluxes to be interfered with each other to illuminate a specimen with an interference fringe of the two branched light fluxes, and an adjusting unit adjusting a height from an optical axis of the illuminating optical system to two collecting points formed on the pupil plane of the objective lens by the two branched light fluxes.

Abstract: A structured illuminating apparatus includes a branching unit branching an exit light flux from a light source into at least two branched light fluxes, an illuminating optical system making the two branched light fluxes to be respectively collected at mutually different positions on a pupil plane of an objective lens and making the two branched light fluxes to be interfered with each other to illuminate a specimen with an interference fringe of the two branched light fluxes, and an adjusting unit adjusting a height from an optical axis of the illuminating optical system to two collecting points formed on the pupil plane of the objective lens by the two branched light fluxes.

Abstract: Provided is a microscope objective lens that sufficiently corrects on-axis and off-axis chromatic aberrations and that has a long working distance. A microscope objective lens OL includes, in order from an object side, a first lens group G1 with positive refractive power and a second lens group G2 with negative refractive power. The first lens group G1 of the microscope objective lens OL includes a diffractive optical element GD including a diffractive optical surface D, and the diffractive optical element GD is arranged at a position closer to the image than a section where a diameter of a light flux passing through the first lens group G1 is the largest.

Abstract: A structured illuminating apparatus includes a branching unit branching an exit light flux from a light source into at least two branched light fluxes, an illuminating optical system making the two branched light fluxes to be respectively collected at mutually different positions on a pupil plane of an objective lens and making the two branched light fluxes to be interfered with each other to illuminate a specimen with an interference fringe of the two branched light fluxes, and an adjusting unit adjusting a height from an optical axis of the illuminating optical system to two collecting points formed on the pupil plane of the objective lens by the two branched light fluxes.

Abstract: Provided is a microscope objective lens that sufficiently corrects on-axis and off-axis chromatic aberrations and that has a long working distance. A microscope objective lens OL includes, in order from an object side, a first lens group G1 with positive refractive power and a second lens group G2 with negative refractive power. The first lens group G1 of the microscope objective lens OL includes a diffractive optical element GD including a diffractive optical surface D, and the diffractive optical element GD is arranged at a position closer to the image than a section where a diameter of a light flux passing through the first lens group G1 is the largest.

Abstract: Provided is a microscope objective lens that sufficiently corrects on-axis and off-axis chromatic aberrations and that has a long working distance. A microscope objective lens OL includes, in order from an object side, a first lens group G1 with positive refractive power and a second lens group G2 with negative refractive power. The first lens group G1 of the microscope objective lens OL includes a diffractive optical element GD including a diffractive optical surface D, and the diffractive optical element GD is arranged at a position closer to the image than a section where a diameter of a light flux passing through the first lens group G1 is the largest.

Abstract: Provided is a microscope objective lens that sufficiently corrects on-axis and off-axis chromatic aberrations and that has a long working distance. A microscope objective lens OL includes, in order from an object side, a first lens group G1 with positive refractive power and a second lens group G2 with negative refractive power. The first lens group G1 of the microscope objective lens OL includes a diffractive optical element GD including a diffractive optical surface D, and the diffractive optical element GD is arranged at a position closer to the image than a section where a diameter of a light flux passing through the first lens group G1 is the largest.

Abstract: Provided is a microscope objective lens that sufficiently corrects on-axis and off-axis chromatic aberrations and that has a long working distance. A microscope objective lens OL includes, in order from an object side, a first lens group G1 with positive refractive power and a second lens group G2 with negative refractive power. The first lens group G1 of the microscope objective lens OL includes a diffractive optical element GD including a diffractive optical surface D, and the diffractive optical element GD is arranged at a position closer to the image than a section where a diameter of a light flux passing through the first lens group G1 is the largest.

Abstract: A structured illuminating apparatus includes a branching unit branching an exit light flux from a light source into at least two branched light fluxes, an illuminating optical system making the two branched light fluxes to be respectively collected at mutually different positions on a pupil plane of an objective lens and making the two branched light fluxes to be interfered with each other to illuminate a specimen with an interference fringe of the two branched light fluxes, and an adjusting unit adjusting a height from an optical axis of the illuminating optical system to two collecting points formed on the pupil plane of the objective lens by the two branched light fluxes.