A method for adjusting a measuring device having an interferometer unit with an optical axis, an optical distance measuring device with a measuring axis and a support slide that is moveable along a slide axis. The measuring axis is first aligned parallel to the slide axis. An adjustment body with a first spherical reflection and/or diffraction surface and a retro reflector at the back side is arranged at the support slide. It is brought into a first confocal position, in which a first center point of the first spherical reflection/diffraction surface coincides with the focus of the spherical wavefront that is emitted from the interferometer unit. The retro reflector defines a vertex that is located close to the first center point, such that the measuring axis of the distance measuring device extends close to the focus of the emitted spherical wavefront. In doing so, Abbe-faults can be reduced or eliminated.

A measurement apparatus includes a filter changing a light amount of an irradiation light, a lens irradiating a surface of a material with the irradiation light, a stage changing a focus position of the irradiation light in a depth direction of the material, an interfering light extractor causing the irradiation light to interfere with reflected light from the material, a detector detecting an intensity of interfering light obtained by interference between the irradiation light and the reflected light, and a controller calculating a height of the surface of the material based on the detected intensity of interfering light while changing a relative focus position of the irradiation light with respect to the material at a given measurement point of the surface of the material. The controller controls the filter or light source based on the detected intensity of interfering light to change the light amount of the irradiation light.

Exemplary apparatus and method are provided for illuminating a sample. With such exemplary apparatus and/or method, it is possible to, using at least one source arrangement, provide at least one first electro-magnetic radiation. Using an optical system of an optics arrangement, it is possible to receive the first electro-magnetic radiation(s), and modifying the at least one first electro-magnetic radiation to be at least one second electro-magnetic radiation so as to be forwarded to the sample. Further, with the optical system, it is possible to extend the at least one second electro-magnetic radiation into or across the sample for a distance of at least 2 times the Raleigh range of a Gaussian beam when the optics arrangement and the sample are stationary with respect to one another. Additionally, using the optical system, it is possible to control a placement of a focus of the at least one second electro-magnetic radiation on or in the sample.

A method and an apparatus for detecting a concave cylinder and a cylindrical diverging lens are disclosed. In particular, a method for non-contact interference detection of a cylindrical shape is disclosed. A cylindrical converging lens and a cylindrical diverging lens are combined with a to-be-tested concave cylinder respectively. Wavefront error data of the combination of the cylindrical diverging lens and the to-be-tested concave cylinder and wavefront error data of the combination of the cylindrical converging lens and the to-be-tested concave cylinder are obtained through interference measurement respectively. Wavefront error data of a combination of the cylindrical diverging lens and the cylindrical converging lens is then obtained through interference measurement. Shape error data of the to-be-tested concave cylinder, the cylindrical diverging lens, and the cylindrical converging lens is obtained respectively by using a difference algorithm and a wavefront recovery algorithm.

Some embodiments of the invention relate to a laser tracker for progressive tracking of a reflective target and for determining the distance to the target having a distance measuring unit, which is designed as an interferometer, for determining a distance change to the target by means of interferometry, a laser beam source for generating measuring radiation for the interferometer, a base, which defines a standing axis, a beam guiding unit for emitting the measuring radiation and for receiving at least a part of the measuring radiation reflected on the target, wherein the beam guiding unit is pivotable by a motor about the standing axis and an inclination axis, which is essentially orthogonal in relation to the standing axis, in relation to the base, and an angle measuring functionality for determining an alignment of the beam guiding unit in relation to the base.

A method and an apparatus for detecting a cylinder and a cylindrical converging lens are disclosed. In particular, a method for non-contact interference detection of a cylindrical shape is disclosed. Two converging lenses which modulate parallel light into cylindrical waves are combined with a to-be-tested cylinder respectively. Wavefront error data of the combination of the converging lens and the to-be-tested cylinder and wavefront error data of the combination of the two cylindrical converging lenses are obtained. Shape error data of the to-be-tested cylinder, the two cylindrical converging lenses is obtained respectively by using a difference algorithm and a wavefront recovery algorithm. In the technical solution, a detection light path is simple, and shape detection of a cylinder with relatively high precision can be implemented without using a high-precision detection tool calibrated in advance. The technical solution is particularly suitable for cylinder processing in the field of optical processing.

In one embodiment, a sensorless adaptive optics imaging system includes a source of light, an optical delivery unit having a wavefront modifying element, and an optical coherence tomography (OCT) sensor configured to acquire OCT images based on light emitted by the source of light and transmitted through the optical delivery unit. The system also includes a processing unit that can: process the OCT images, and determine an adjustment of parameters of the wavefront modifying element. In some embodiments, the system includes a multi-photon microscopy (MPM) sensor that acquires MPM images based on the light transmitted through the optical delivery unit.

Exemplary apparatus and method are provided for illuminating a sample. With such exemplary apparatus and/or method, it is possible to, using at least one source arrangement, provide at least one first electro-magnetic radiation. Using an optical system of an optics arrangement, it is possible to receive the first electro-magnetic radiation(s), and modifying the at least one first electro-magnetic radiation to be at least one second electro-magnetic radiation so as to be forwarded to the sample. Further, with the optical system, it is possible to extend the at least one second electro-magnetic radiation into or across the sample for a distance of at least 2 times the Raleigh range of a Gaussian beam when the optics arrangement and the sample are stationary with respect to one another. Additionally, using the optical system, it is possible to control a placement of a focus of the at least one second electro-magnetic radiation on or in the sample.

A method for adjusting a measuring device having an interferometer unit with an optical axis, an optical distance measuring device with a measuring axis and a support slide that is moveable along a slide axis. The measuring axis is first aligned parallel to the slide axis. An adjustment body with a first spherical reflection and/or diffraction surface and a retro reflector at the back side is arranged at the support slide. It is brought into a first confocal position, in which a first center point of the first spherical reflection/diffraction surface coincides with the focus of the spherical wavefront that is emitted from the interferometer unit. The retro reflector defines a vertex that is located close to the first center point, such that the measuring axis of the distance measuring device extends close to the focus of the emitted spherical wavefront. In doing so, Abbe-faults can be reduced or eliminated.

A phase-resolved heterodyne shearing interferometer has been developed for high-rate, whole field observations of transient surface motion. The sensor utilizes polarization multiplexing and multiple carrier frequencies to separate each segment of a shearing Mach-Zehnder interferometer. Post-processing routines have been developed to recombine the segments by extracting the scattered object phase from Doppler shifted intermediate carrier frequencies, providing quantitative relative phase changes and information to create variable shear, phase resolved shearographic fringe patterns without temporal or spatial phase shifting.