An interferometric distance-measurement device includes a multi-wavelength light source which provides a beam having at least three different wavelengths. An interferometer unit splits the beam into measuring and reference beams. The measuring beam propagates in the direction of a measuring reflector movable along a measuring axis and undergoes a back-reflection, and the reference beam propagates in the direction of a stationary reference reflector and undergoes a back-reflection. The back-reflected measuring and reference beams interfere with each other in an interference beam. A detection unit splits the interference beam such that several phase-shifted partial interference signals result for each wavelength. A signal processing unit determines absolute position information regarding the measuring reflector from the partial interference signals of different wavelengths and an additional coarse position signal.

The present invention relates to a method of reducing phase-error signal degradation in a characteristic spectrum produced by a Fourier Transform interferometer, comprising the steps of: (1) Receiving, upon the detector array, a light beam comprised of a plurality of light channels, each of the light channels being received at a corresponding location upon the detector array; (II) Producing, for each corresponding location, a Raw Location-Specific Signal (LSS) from the received light channels; (III) for each Raw LSS, calculating an Off-Axis Path Difference (OxPaDE) scaling function dependent upon a distance and direction of the corresponding location from a target location; (IV) coordinate-transforming each Raw LSS using their corresponding calculated OxPaDE function to produce an Adjusted LSS; (V) averaging each Adjusted LSS to produce a Combined Signal; and (VI) inverse Fourier-Transforming the Combined Signal to produce the characteristic spectrum of the received light beam as a function of wavenumber.

The present invention relates to a method of reducing phase-error signal degradation in a characteristic spectrum produced by a Fourier Transform interferometer, comprising the steps of: (1) Receiving, upon the detector array, a light beam comprised of a plurality of light channels, each of the light channels being received at a corresponding location upon the detector array; (II) Producing, for each corresponding location, a Raw Location-Specific Signal (LSS) from the received light channels; (III) for each Raw LSS, calculating an Off-Axis Path Difference (OxPaDE) scaling function dependent upon a distance and direction of the corresponding location from a target location; (IV) coordinate-transforming each Raw LSS using their corresponding calculated OxPaDE function to produce an Adjusted LSS; (V) averaging each Adjusted LSS to produce a Combined Signal; and (VI) inverse Fourier-Transforming the Combined Signal to produce the characteristic spectrum of the received light beam as a function of wavenumber.

A light measurement device that maintains high measurement precision. The light measurement device includes: light source that irradiates light upon measurement object; branch part that splits transmitted light or reflected light from measurement object; phase-changing unit that changes the phase of one beam of the branched light beams; phase-fixing unit that maintains the phase of the other beam of the branched light beams; adjustment mechanism, which is provided in phase-changing unit or phase-fixing unit, for adjusting the propagation direction of light; multiplexer that causes the light emitted by each of phase-changing unit and phase-fixing unit to interfere with each other; detection unit that detects light that is interfered with by multiplexer; and control unit that controls the adjustment mechanism on the basis of the luminance values of an interference image that is detected by detection unit and adjusts the propagation direction of light in phase-changing unit or phase-fixing unit.

A position measurement system includes an interferometer to determine a position of an object. The interferometer is arranged to generate a first, second and third signals representative of the position by irradiating respective first, second and third areas of a reflective surface of the object. Along a line, the first and second areas are at a first distance relative to each other, the second and third areas are at a second distance relative to each other, and the first and third areas are at a third distance relative to each other. The interferometer is arranged to provide a rotation signal representative of a rotation of the object along an axis based on the first, second and third signals. The axis is parallel to the reflective surface and perpendicular to the line.

What is proposed is a device (1) for optically measuring an object, comprising an interferometer (2) having a measurement arm (21), wherein the measurement arm (21) is provided for optically measuring the object, and comprising a focusing element (3) arranged within the measurement arm (21). According to the invention, the device (1) comprises a first retardation element (4) arranged within the measurement arm (21) and downstream of the focusing element (3), wherein the first retardation element (4) has a movable displacement element (42), by means of which the optical path length of the beam path of the measurement arm (21) is variable.

Various systems and methods for sequential angle illumination to achieve ultra-high resolution optical coherence tomography (OCT) images. One example OCT system includes a light source, a beam divider, sample arm optics, a detector, and a processor. The light source generates a light beam to illuminate the sample. The beam divider separates the light beam into reference and sample arms. The sample arm optics sequentially illuminates a location in the sample with the light beam from different angles. The detector receives light returned from the reference arm and the sample illuminated at each angle and generates signals. The processor combines the signals to generate an image, which has a transverse resolution that is higher than the transverse resolution achieved from the signal generated from a single angle.

A light detecting module that detects interference light that has exited an exit end surface of an optical fiber in an OCT instrument includes: a ball lens including an incident surface entered by the interference light that has exited the exit end surface, and an exit surface exited by the interference light that has entered the incident surface; and a photodiode including a detecting surface entered by the interference light that has exited the exit surface. The interference light obliquely enters the incident surface with respect to a perpendicular line at an incident position of the interference light. The interference light obliquely exits the exit surface with respect to a perpendicular line at an exit position of the interference light. The interference light obliquely enters the detecting surface with respect to a perpendicular line at an incident position of the interference light.

The present invention provides a measurement apparatus for measuring a position of an object, comprising a reflecting portion provided on the object and having a surface on which reflectors configured to retroreflect light are arrayed, an optical system configured to cause first light to be incident on the surface, receive second light as reflected light of the first light, cause third light generated from the second light to be incident on the surface, and receive fourth light as reflected light of the third light, and a processor configured to determine the position of the object based on a detection result of the forth light, wherein the optical system is configured such that a displacement between optical paths of the first light and the second light is corrected by a displacement between optical paths of the third light and the fourth light.

Stackable and/or nestable box having a bottom wall and a side wall which rises from the bottom wall and which is defined by side panels, a front panel and a rear panel. The side panels include at least one recessed portion which is recessing from the containment volume and at least one portion protruding towards the containment volume. The box is configured to be nested within another box and to be stacked with other boxes or other containers with dimensions compatible with, or close to, the dimensions of box.