The present invention provides a phase difference observation apparatus that can reduce the size of the apparatus by not requiring an additional imaging unit and can suppress deterioration of the phase difference image due to the meniscus. The phase difference observation apparatus of the present invention includes a light source; an illumination optical system that guides illumination light from the light source to an observation target object in a cell culture vessel; an imaging optical system that forms an optical image of the observation target object on an image sensor; and a control unit. The illumination optical system includes a spatial modulator that changes an intensity distribution of the illumination light, the control unit contains intensity distribution correction information associating a position of the imaging optical system with respect to the cell culture vessel with an intensity distribution of illumination light at the position of the imaging optical system, the control unit acquires imaging system position information, which is the position of the imaging optical system, and the control unit changes an intensity distribution of illumination light in the spatial modulator on the basis of the imaging system position information and the intensity distribution correction information.

An immersion lithographic apparatus is provided with a liquid confinement structure which defines at least in part a space configured to contain liquid between the projection system and the substrate. In order to reduce the crossing of the edge of the substrate which is being imaged (which can lead to inclusion of bubbles in the immersion liquid), the cross-sectional area of the space in a plane parallel to the substrate is made as small as possible. The smallest theoretical size is the size of the target portion which is imaged by the projection system. In an embodiment, the shape of a final element of the projection system is also changed to have a similar size and/or shape in a cross-section parallel to the substrate to that of the target portion.

A phase difference observation apparatus includes a light source; an illumination guide to guide illumination light from the light source to an observation target object in a cell culture vessel; an optical imager to form an optical image of the observation target object on an image sensor; and a controller. The illumination guide includes a spatial modulator to change an intensity distribution of the illumination light; the controller contains intensity distribution correction information associating a position of the imaging guide with respect to the cell culture vessel with an intensity distribution of illumination light at the position of the optical imager; the controller acquires imaging system position information, which is the position of the optical imager; and the controller changes an intensity distribution of illumination light in the spatial modulator on the basis of the imaging system position information and the intensity distribution correction information.

An enhanced single particle interferometric reflectance imaging system includes an illumination source configured to produce illumination light along an illumination path toward a target substrate. The target substrate can be configured to reflect the illuminating light along one or more collection paths toward one or more imaging sensors. The target substrate includes a base substrate having a first reflecting surface and a transparent spacer layer having a first surface in contact with the first reflecting surface and a second reflecting surface on a side opposite to the first surface. The transparent spacer layer has a predefined thickness that is determined as a function of a wavelength of the illuminating light and produces a predefined radiation pattern of optical scattering when nanoparticles are positioned on or near the second reflective surface. In addition, one or more of the collection paths can also include an amplitude mask selected to match the radiation pattern.

Various methods, systems and apparatus are provided for imaging and sensing using interferometry. In one example, a system includes an interferometer; a light source that can provide light to the interferometer at multiple wavelengths (.sub.i); and optical path delay (OPD) modifying optics that can enhance contrast in an interferometer output associated with a sample. The light can be directed to the sample by optics of the interferometer. The interferometer output can be captured by a detector (e.g., a camera) at each of the multiple wavelengths (.sub.i). In another example, an apparatus includes an add-on unit containing OPD that can enhance contrast in an interferometer output associated with a sample illuminated by light at a defined wavelength (.sub.i). A detector can be attached to the add-on unit to record the interferometer output at the defined wavelength (.sub.i).

A method of modifying a lithographic apparatus comprising an illumination system for providing a radiation beam, a support structure for supporting a patterning device to impart the radiation beam with a pattern in its cross-section, a first lens for projecting the radiation beam at the patterning device with a first magnification, a substrate table for holding a substrate, and a first projection system for projecting the patterned radiation beam at a target portion of the substrate with a second magnification. The first lens and the first projection system together provide a third magnification. The method comprises reducing by a first factor the first magnification to provide a second lens for projecting the radiation beam with a fourth magnification; and increasing by the first factor the second magnification to provide a second projection system for projecting the patterned radiation beam at the target portion of the substrate with a fifth magnification.

A measurement apparatus is configured to measure a position of an object based on a first phase signal and a second phase signal whose phases are different from each other and includes a compensator configured to compensate for a fluctuation in a phase difference between the first phase signal and the second phase signal based on a frequency of at least one of the first phase signal and the second phase signal.

The microscope apparatus includes: an illumination light irradiation unit that irradiates an object to be observed with illumination light for phase-contrast measurement; a transmission type display unit on which light, which is transmitted through the object to be observed due to irradiation with the illumination light for phase-contrast measurement, is incident; and an imaging unit that images the object to be observed by detecting the light transmitted through the transmission type display unit. The transmission type display unit displays patterns where transmission density varies for every light having a plurality of wavelengths included in the light transmitted through the object to be observed.

An achromatic phase-contrast imaging apparatus for examining an object of interest is provided which comprises two different phase gratings which have different pitches. Thus, the imaging apparatus yields phase-contrast information for two different energies. Thus, phase-information over a wider energy band can be used.

An achromatic phase-contrast imaging apparatus for examining an object of interest is provided which comprises two different phase gratings which have different pitches. Thus, the imaging apparatus yields phase-contrast information for two different energies. Thus, phase-information over a wider energy band can be used.