During one or more active periods of time over which at least one of an amplitude, frequency, or phase of one or more optical wave(s) are modified, the optical wave(s) overlap with and interact with a gaseous cloud of IAMs and transfer portions of the among different distributions of momentum states. Control signals for controlling aspects of the optical wave(s) are determined based at least in part on (1) a constraint determined based at least in part on a set of optical wave parameters, and a set of quantum state parameters, where two or more of the quantum state parameters do not satisfy the constraint, and/or (2) a partial derivative of one or more quantum states associated with the IAMs, where the partial derivative is with respect to an optimization parameter determined based at least in part on the one or more optical waves or the estimation parameter.

The invention provides a wavelength tracking system comprising a wavelength tracking unit and an interferometer system. The wavelength tracking unit has reflection surfaces at stabile positions providing a first reflection path with a first path length and a second reflection path with a second path length. The first path length is substantially larger than the second path length. The interferometer system comprises: a beam splitter to split a light beam in a first measurement beam and a second measurement beam; at least one optic element to guide the first measurement beam, at least partially, along the first reflection path and the second measurement beam, at least partially, along the second reflection path; a first light sensor arranged at an end of the first reflection path to receive the first measurement beam and to provide a first sensor signal on the basis of the first measurement beam; a second light sensor arranged at an end of the second reflection path to receive the second measurement beam and to provide a second sensor signal on the basis of the second measurement beam; and a processing unit to determine a wavelength or change in wavelength on the basis of the first sensor signal and the second sensor signal.

Interferometer (10) for the real-time measurement of absolute distances and/or relative position movements between a first and a second machine part, comprising a measurement unit (20) and a reflector unit (40).

wherein the measurement unit (20) comprises a housing (21) with at least one wall made of heat-conducting material,

wherein several measurement elements are arranged in the housing (21), wherein the measurement elements comprise:

a laser source (22), a Peltier element (24) and a digital control (23)

wherein the measurement elements are thermally coupled to the wall of the housing (21) made of heat-conducting material.

According to the disclosure, a position detection system using laser light interferometry is proposed, capable of measuring the positions and displacements of an object relative to and within an XYZ system of coordinates, the system using a holder comprising a mounting surface for the object, the mounting surface being oriented in the XY plane of the XYZ system of coordinates, several X, Y and Z measuring mirrors as well as a plurality of X, Y, and Z optical devices, each optical device structured to emit and direct an X, Y or Z laser light beam to and from a respective X, Y or Z measuring mirror and structured to detect and convert at least part of the X, Y or Z laser light beams reflected by the respective X, Y or Z measuring mirrors into electric measuring signals, the electric measuring signals comprising at least information as to the X, Y and Z position of the object, wherein, for measuring the Z position of the object, the at least one Y laser light beam is directed parallel to the XY plane to and from a Y measuring mirror positioned perpendicular to the XY plane and the at least one Z laser light beam is directed under an angle relative to the XY plane to and from a Z measuring mirror.

By directing the Y laser light beam parallel to the XY plane to and from a Y measuring mirror positioned perpendicular to the XY plane and directing the Z laser light beam under an angle relative to the XY plane to and from a Z measuring mirror, the optics of the position detection system can be simplified as any additional Z measuring mirror can be obviated. Particularly, this results in less occupied work volume in the direct vicinity where semiconductor and integrated circuit manufacturing processes.

Methods are known for implementing general optical functions using wave splitters. However, these methods rely on these wave splitters having maximal extinction ratio, which is difficult to achieve in practice. The present invention provides methods for automatically adjusting wave splitters to provide maximal extinction ratio.

A fiber optic transducer is provided. The fiber optic transducer includes a fixed portion configured to be secured to a body of interest, a moveable portion having a range of motion with respect to the fixed portion, a spring positioned between the fixed portion and the moveable portion, and a length of fiber wound between the fixed portion and the moveable portion. The length of fiber spans the spring. The fiber optic transducer also includes a mass engaged with the moveable portion. In one disclosed aspect of the transducer, the mass envelopes the moveable portion.

Disclosed is a method and corresponding apparatus for determining an absolute optical distance between two reflecting surfaces that make up an interferometric cavity, the method comprising: moving an illumination spot in a back focal plane of an interferometer along a trajectory that has a nonzero radial component relative to an optical axis to cause different radial positions for the illumination spot along the trajectory while synchronously acquiring images of interferograms of the interferometric cavity; and using one or more electronic processors to analyze the images to determine a functional dependence of an optical path difference (OPD) for the interferometric cavity versus radial position for the illumination spot and extract the absolute optical distance between the two reflecting surfaces based on the determined functional dependence.

Disclosed is a method and corresponding apparatus for determining an absolute optical distance between two reflecting surfaces that make up an interferometric cavity, the method comprising: moving an illumination spot in a back focal plane of an interferometer along a trajectory that has a nonzero radial component relative to an optical axis to cause different radial positions for the illumination spot along the trajectory while synchronously acquiring images of interferograms of the interferometric cavity; and using one or more electronic processors to analyze the images to determine a functional dependence of an optical path difference (OPD) for the interferometric cavity versus radial position for the illumination spot and extract the absolute optical distance between the two reflecting surfaces based on the determined functional dependence.

The invention relates to a multi-axis differential interferometer (1) for measuring a displacement and/or rotation between a first reflective surface (21, 321) and a second reflective surface (81, 381), wherein said measuring is carried out using at least two pairs of beams, wherein each pair is formed by a measurement beam (Mb) to be emitted onto a first one (21, 321) of said reflective surfaces, and a reference beam (Rb) to be emitted onto another one (81, 381) of said reflective surfaces, said interferometer (1) comprising: a first optical module (20) and a second optical module (40), wherein each optical module (20, 40) is configured for receiving a respective coherent beam and for creating one of said pairs therefrom. The invention further relates to a lithography system comprising such an interferometer and to a method for assembling such a multi-axis differential interferometer.

In certain embodiments methods of identifying T cell receptors that respond to specific target cell antigens are provided, where the methods comprise providing a substrate bearing a plurality of target cells (e.g., mammalian cells); contacting the target cells on the substrate with CD8+ T cells; and using label-free optical imaging to identify an increase in mass of a T-cell and/or a decrease in mass of a target cell, where an increase in mass of a T cell and/or a decrease in mass of a target cell is an indicator that said T cell bears a T cell receptor activated by antigens presented on said target cell.