An interference observation apparatus includes a light source, a splitting beam splitter, a combining beam splitter, a beam splitter, a mirror, a beam splitter, a mirror, a piezo element, a stage, an imaging unit, an image acquisition unit, and a control unit. An interference optical system from the splitting beam splitter to the combining beam splitter forms a Mach-Zehnder interferometer. The mirror freely moves in a direction perpendicular to a reflecting surface of the mirror. The total number of times of respective reflections of first split light and second split light in the interference optical system is an even number.

A confocal microscope for determination of a layer thickness comprises: a focus adjusting device configured to adjust a relative displacement between a focus position of the illumination light and a specimen position along an optical axis, wherein measurement signals belonging to different settings of the focus adjusting device can be recorded; an evaluation device for determining a specimen layer thickness as follows: determine intensity band positions of two intensity bands in a measurement graph recorded by a light measuring device, the measurement graph indicating a light intensity in dependence of the focus position; determine a layer thickness on the basis of a positional difference between the intensity band positions; and determine the layer thickness using a mathematical model which describes for overlapping intensity bands a dependence of the intensity band positions on a light wavelength and the layer thickness, considering interference of the illumination light at the layer.

An optical measurement apparatus (100) combines confocal measurement and low coherence interferometric measurement. The apparatus (100) comprises an interferometric measurement subsystem (102) and a confocal measurement subsystem (104) disposed within a housing (101). An optical combiner (136) is configured to provide the interferometric measurement subsystem (102) and the confocal measurement subsystem (104) with irradiative access to a region to be measured located at a substantially static target location. The interferometric measurement subsystem (102) and the confocal measurement subsystem (104) are respectively configured to image longitudinally in respect of a first subregion (162) and a second subregion (164) in the region to be measured. the second subregion (164) being axially spaced from the first subregion (162). A processing resource (152. 154) is operably coupled to the interferometric measurement subsystem (102) and the confocal measurement subsystem (104), and configured to calculate a first range in respect of the first subregion (162) and a second range in respect of the second subregion (164).

Methods and systems for focusing and measuring by mean of an interferometer device, having an optical coherence tomography (OCT) focusing system, by separately directing an overlapped measurement and reference wavefront towards a focus sensor and towards an imaging sensor; where a predefined focusing illumination spectrum of the overlapped wavefront is directed towards the focus sensor, and where a predefined measurement illumination spectrum of the overlapped wavefront is directed towards the imaging sensor. Methods and systems for maintaining focus of an interferometer device, having an OCT focusing system, during sample's stage moves.

A differential filtering chromatic confocal microscopic system comprises a chromatic dispersion objective for receiving and axially dispersing a broadband light from a light source and projecting dispersed lights onto an object thereby forming an object light reflected therefrom; an optical modulation module for dividing the object light into a first and a second object lights; a pair of optical intensity sensing module, respectively having a spatial filter with a different pinhole diameter or a slit width from each other, for detecting the first and second object lights, thereby obtaining a plurality of first and second optical intensity signals; and a signal processor for respectively processing the plurality of first and second optical intensity signals thereby obtaining a plurality of differential rational values of optical intensity and determining a corresponding object depth associated with each differential rational value according to a relation between signal intensity ratio and object surface depth.

Optical coherence tomography (OCT) imaging systems are provided including a source of broadband optical radiation coupled to a sample arm of the OCT imaging system; a beam shaping optical assembly in the sample arm, the beam shaping optical assembly being configured to receive optical radiation from the source as a beam of optical radiation and to shape the spatial profile of the beam of optical radiation; a scan mirror assembly coupled to the beam shaping optical assembly; and objective lens assembly coupled to the beam shaping optical assembly. The beam shaping optical assembly includes a lens assembly configured to change a NA of the OCT system without changing a focus; to change a focus of the OCT system without changing a NA of the system; or to change both the NA and the focus of the OCT system responsive to a control input.

Optical coherence tomography (OCT) imaging systems are provided including a source of broadband optical radiation coupled to a sample arm of the OCT imaging system; a beam shaping optical assembly in the sample arm, the beam shaping optical assembly being configured to receive optical radiation from the source as a beam of optical radiation and to shape the spatial profile of the beam of optical radiation; a scan mirror assembly coupled to the beam shaping optical assembly; and objective lens assembly coupled to the beam shaping optical assembly. The beam shaping optical assembly includes a lens assembly configured to change a NA of the OCT system without changing a focus; to change a focus of the OCT system without changing a NA of the system; or to change both the NA and the focus of the OCT system responsive to a control input.

The present invention provides a novel simple, portable, compact and inexpensive approach for interferometric optical thickness measurements that can be easily incorporated into an existing microscope (or other imaging systems) with existing cameras. According to the invention, the interferometric device provides a substantially stable, easy to align common path interferometric geometry, while eliminating a need for controllably changing the optical path of the beam. To this end, the inexpensive and easy to align interferometric device of the invention is configured such that it applies the principles of the interferometric measurements to a sample beam only, being a single input into the interferometric device.

An interference observation apparatus includes a light source which outputs incoherent light, a beam splitter, a sample holding table, an objective lens, a reference mirror, a lens, an aberration correction plate, a piezo element, a tube lens, a beam splitter, an imaging unit, a photodetector, an image acquisition unit, and a control unit. The control unit obtains an interference intensity of combined light on the basis of a detection signal output from the photodetector, and adjusts an interference optical system to increase the interference intensity.

The present invention provides a novel simple, portable, compact and inexpensive approach for interferometric optical thickness measurements that can be easily incorporated into an existing microscope (or other imaging systems) with existing cameras. According to the invention, the interferometric device provides a substantially stable, easy to align common path interferometric geometry, while eliminating a need for controllably changing the optical path of the beam. To this end, the inexpensive and easy to align interferometric device of the invention is configured such that it applies the principles of the interferometric measurements to a sample beam only, being a single input into the interferometric device.