Abstract: A lens system is configured to form an image of an object on an imaging surface of an image sensor. A branching optical system is configured such that an image-forming light flux in the lens system is split and propagated into a plurality of optical paths having different optical path lengths and such that the principal rays of a plurality of image-forming light fluxes obtained after the splitting are incident on a predetermined region of the image sensor.

Abstract: A sample shape measuring method includes a step of preparing illumination light passing through a predetermined illumination region, a step of applying the illumination light to a sample, and a predetermined processing step. The predetermined illumination region is set so as not to include the optical axis at a pupil position of the illumination optical system and is set such that the illumination light is applied to part of the inside of the pupil and the outside of the pupil at a pupil position of the observation optical system. The predetermined processing step includes a step of receiving light, a step of obtaining the quantity of light, a step of calculating the difference or the ratio between the quantity of light and a reference quantity of light, and a step of calculating the amount of tilt in the surface of the sample from the difference or the ratio.

Abstract: A sample shape measuring method includes a step of preparing illumination light passing through a predetermined illumination region, a step of applying the illumination light to a sample, and a predetermined processing step. The predetermined illumination region is set such that the illumination light is applied to part of inside of a pupil and outside of the pupil, a light intensity of the illumination light incident on the predetermined illumination region differs between a center and a periphery. The predetermined processing step includes a step of receiving light transmitted through the observation optical system, a step of obtaining a quantity of light of the received light, a step of calculating a difference or a ratio between the quantity of light and a reference quantity of light, and a step of calculating an amount of tilt in a surface of the sample from the difference or the ratio.

Abstract: A sample shape measuring method includes a step of preparing illumination light passing through a predetermined illumination region, a step of applying the illumination light to a sample, and a predetermined processing step. The predetermined illumination region is set such that the illumination light is applied to part of inside of a pupil and outside of the pupil, a light intensity of the illumination light incident on the predetermined illumination region differs between a center and a periphery. The predetermined processing step includes a step of receiving light transmitted through the observation optical system, a step of obtaining a quantity of light of the received light, a step of calculating a difference or a ratio between the quantity of light and a reference quantity of light, and a step of calculating an amount of tilt in a surface of the sample from the difference or the ratio.

Abstract: A sample shape measuring method includes a step of preparing illumination light passing through a predetermined illumination region, a step of applying the illumination light to a sample, and a predetermined processing step. The predetermined illumination region is set so as not to include the optical axis at a pupil position of the illumination optical system and is set such that the illumination light is applied to part of the inside of the pupil and the outside of the pupil at a pupil position of the observation optical system. The predetermined processing step includes a step of receiving light, a step of obtaining the quantity of light, a step of calculating the difference or the ratio between the quantity of light and a reference quantity of light, and a step of calculating the amount of tilt in the surface of the sample from the difference or the ratio.

Abstract: A photoacoustic microscope includes an objective lens that irradiates a specimen with excitation light, a light scanning unit that deflects the excitation light to scan the specimen, an acoustic lens that converts a wavefront of a photoacoustic wave generated by the specimen due to irradiation with the excitation light, a photoacoustic wave detection unit that detects the photoacoustic wave from the acoustic lens, a drive unit that displaces at least one of the acoustic lens and the photoacoustic wave detection unit, and a control unit that controls the drive unit, in synchronization with scanning of the excitation light by the light scanning unit, so that the photoacoustic wave is incident on the photoacoustic wave detection unit perpendicularly.

Abstract: Provided is a photoacoustic microscope, including: an objective lens configured to collect excitation light into a specimen, the excitation light in a wavelength range that is absorbed by an object to be observed; a detection light optical system configured to (i) form an image of a point light source of detection light in a middle portion of a pupil of the objective lens, the detection light having a wavelength that is different from the wavelength range of the excitation light, and (ii) emit the detection light onto the specimen by means of the objective lens; an optical scanning unit configured to deflect the excitation light and the detection light that enter the objective lens, for scanning the specimen; and a light detection unit configured to detect reflected light of the detection light that is reflected by the specimen.

Abstract: A photoacoustic microscope includes an objective lens that irradiates a specimen with excitation light, a light scanning unit that deflects the excitation light to scan the specimen, an acoustic lens that converts a wavefront of a photoacoustic wave generated by the specimen due to irradiation with the excitation light, a photoacoustic wave detection unit that detects the photoacoustic wave from the acoustic lens, a drive unit that displaces at least one of the acoustic lens and the photoacoustic wave detection unit, and a control unit that controls the drive unit, in synchronization with scanning of the excitation light by the light scanning unit, so that the photoacoustic wave is incident on the photoacoustic wave detection unit perpendicularly.

Abstract: A microscope objective lens has an aspheric-surface lens, and a first lens nearest to an object side is a negative lens. It is desirable that at least any one surface of the first lens nearest to the object side is an aspheric surface. Moreover, it is desirable that the microscope objective lens satisfies the following conditional expression (1) ?20<f1/f<?0.1??(1) where, f1 denotes a focal length of the first lens nearest to the object side, and f denotes a focal length of the overall microscope objective lens system.

Abstract: Provided is a photoacoustic microscope, including: an objective lens configured to collect excitation light into a specimen, the excitation light in a wavelength range that is absorbed by an object to be observed; a detection light optical system configured to (i) form an image of a point light source of detection light in a middle portion of a pupil of the objective lens, the detection light having a wavelength that is different from the wavelength range of the excitation light, and (ii) emit the detection light onto the specimen by means of the objective lens; an optical scanning unit configured to deflect the excitation light and the detection light that enter the objective lens, for scanning the specimen; and a light detection unit configured to detect reflected light of the detection light that is reflected by the specimen.

Abstract: A microscope objective lens satisfies the following conditional expressions (1) and (2). 0.05<NA<0.4??(1) 3 mm<D/NA<50 mm??(2) where, NA denotes a numerical aperture on an object side of the microscope objective lens, and D denotes a total thickness of the microscope objective lens.

Abstract: A Fresnel optical element has a plurality of slopes that refract or reflect light, and the variation of the slope angle between adjacent slopes is constant.

Abstract: A Fresnel optical element has a plurality of slopes that refract or reflect light, and the variation of the slope angle between adjacent slopes is constant.