Disclosed is a surface sensing apparatus, one embodiment having a source of coherent radiation capable of outputting wavelength emissions to create a first illumination state to illuminate a surface and create a first speckle pattern, an emission deviation facility capable of influencing the emission to illuminate the surface and create a second illumination state and a second speckle pattern, and a sensor capable of sensing a representation of the first and a second speckle intensity from the first and second speckle pattern. Also disclosed are methods of sensing properties of the surface, one embodiment comprising the steps of illuminating the surface having a first surface state with the source of coherent radiation emission, sensing a first speckle intensity from the surface, influencing a relationship of the surface to the emission to create a second surface state and sensing a second speckle intensity from the surface at the second surface state.

The application discloses an atom interferometer comprising an optical cavity and method of operation thereof. The atom interferometer includes a vacuum chamber, an optical cavity, a source for providing a cloud of atoms in the optical cavity in use, and one or more light sources. The one or more light sources are for generating, in the cavity, in use a first light beam having a first polarisation and at a first frequency for a two-photon interaction in the atoms; and a counterpropagating second light beam having a second polarisation orthogonal to the first polarisation and at a second frequency for the two-photon interaction in the atoms. The atom interferometer also includes an electro-optic element arranged in the cavity to be operable to simultaneously change: the resonant frequency of the cavity for light in the first polarisation to track changes in the frequency of the first light beam to compensate for the doppler shift of the falling atoms in use; and the resonant frequency of the cavity for light in the second polarisation to track changes in frequency of the counterpropagating second light beam to compensate for the doppler shift of the falling atoms in use.

Systems, methods, and media for multiple beam optical coherence tomography are provided which, in some embodiments, include: a light source; a splitter that outputs a fraction of light to various waveguides; optical components that receive light from the waveguides and direct the light as beams that simultaneously impinge a sample at different lateral positions, and collect backscattered light from the lateral positons; another splitter that outputs a fraction of light to waveguides of a reference arm as reference light samples; a mixer that receives the backscattered light samples and the reference light samples, and combines each backscattered sample with a corresponding reference sample such that the mixer outputs fringes; and a detector that receives the fringes, and outputs OCT signals, each indicative of a structure of the sample at a respective lateral position.

An interferometer and an imager may include a tunable light source, a beam splitter, a digital imager, and a processor system. The tunable light source may be configured to emit a beam. The beam splitter may be configured to direct the beam toward a sample with a floor surface and a raised surface feature. The digital imager may be configured to receive a reflected beam and to generate an image based on the reflected beam. The reflected beam may be a coherent addition of a first reflection of the beam off a reference plate and a second reflection of the beam off the raised surface feature and third reflection of the beam off the floor surface. The processor system may be coupled to the digital imager and may be configured to determine a distance between the reference surface and the feature surface based on the image. A second digital imager may also be configured to receive a reflected beam and scattered beam to generate a two-dimensional grayscale image of the surface based on these beams and may also be configured to receive fluorescent light generated by the incident light to generate a two-dimensional gray scale an image of the surface based on fluorescent emission.

An interferometer and an imager may include a tunable light source, a beam splitter, a digital imager, and a processor system. The tunable light source may be configured to emit a beam. The beam splitter may be configured to direct the beam toward a sample with a floor surface and a raised surface feature. The digital imager may be configured to receive a reflected beam and to generate an image based on the reflected beam. The reflected beam may be a coherent addition of a first reflection of the beam off a reference plate and a second reflection of the beam off the raised surface feature and third reflection of the beam off the floor surface. The processor system may be coupled to the digital imager and may be configured to determine a distance between the reference surface and the feature surface based on the image. A second digital imager may also be configured to receive a reflected beam and scattered beam to generate a two-dimensional grayscale image of the surface based on these beams and may also be configured to receive fluorescent light generated by the incident light to generate a two-dimensional gray scale an image of the surface based on fluorescent emission.

A system for a target image reconstruction includes a stepped frequency transmitter configured to emit a stepped frequency waveform having different constant frequencies at different periods of time and a modulator configured to modulate the stepped frequency waveform emitted at each period of time with a modulation signal to output a modulated stepped frequency waveform with an increased bandwidth. The system includes a transceiver configured to transmit the modulated stepped frequency waveform to a target and to accept reflection of the modulated stepped frequency waveform reflected from the target, a mixer to interfere the unmodulated stepped frequency waveform and the reflection of the modulated stepped frequency waveform to produce a beat signal of the interference of the unmodulated stepped frequency waveform with the reflection of the modulated stepped frequency waveform, and a signal processor to reconstruct an image of the target from the beat signal.

A method including: scanning a sample over a period of time using an electro-magnetic radiation source, the period of time including a first time period and a second time period, a sample portion of the electro-magnetic radiation source being directed to the sample in a sample arm of an optical interferometric system, and a reference portion of the electro-magnetic radiation source being directed to a reference arm of the optical interferometric system; applying, using a phase modulator, a phase shift comprising a first phase shift and a second phase shift to at least one of the reference portion or the sample portion of the electro-magnetic radiation source, the first phase shift being applied during the first time period and the second phase shift being applied during the second time period, the second phase shift having a difference of 90 degrees from the first phase shift; acquiring in-phase data based on a first interference between first backscattered electro-magnetic radiation during the first time period and the at least one of the reference portion or the sample portion subjected to the first phase shift; acquiring quadrature data based on a second interference between second backscattered electro-magnetic radiation during the second time period and the at least one of the reference portion or the sample portion subjected to the second phase shift; and determining a complex interference signal based on the in-phase data and the quadrature data.

Provided is a device for measuring a lens three-dimensional profile based on laser wavenumber scanning, including: a semiconductor laser for emitting coherent light; a beam splitter for dividing the coherent light into two parts; an optical wedge; a CCD camera for capturing an interference image; a computer for processing image information; a laser controller for adjusting an operating temperature and an operating current of the semiconductor laser; and a bilateral telecentric lens. The coherent light is reflected by the optical wedge and then reaches the bilateral telecentric lens through the beam splitter, to form a first reflected light path. The coherent light is reflected by the measured lens, and then reaches the bilateral telecentric lens through the beam splitter, to form a second reflected light path. The first reflected light path and the second reflected light path form an interference image after passing through the bilateral telecentric lens.

An acousto-optic modulator (AOM) laser frequency shifter system includes a laser configured to generate an incident beam, a first optical splitter optically coupled to the laser and configured to split the incident beam into at least one portion of the incident beam, at least one phase-shift channel optically coupled to the first optical splitter and configured to generate at least one frequency-shifted beam with an acousto-optic modulator (AOM) from the at least one portion of the incident beam received from the first optical splitter, and a second optical splitter configured to receive the at least one frequency-shifted beam from the at least one phase-shift channel and configured to direct the at least one frequency-shifted beam to an interferometer configured to acquire an interferogram of a sample with the at least one frequency-shifted beam.

An apparatus can be provided which can include a laser arrangement which can be configured to provide a laser radiation, and can include an optical cavity. The optical cavity can include a dispersive optical first arrangement which can be configured to receive and disperse at least one first electro-magnetic radiation so as to provide at least one second electro-magnetic radiation. Such cavity can also include an active optical modulator second arrangement which can be configured to receive and modulate the at least one second radiation so as to provide at least one third electro-magnetic radiation. The optical cavity can further include a dispersive optical third arrangement which can be configured to receive and disperse at least one third electro-magnetic radiation so as to provide at least one fourth electro-magnetic radiation. For example, actions by the first, second and third arrangements can cause a spectral filtering of the fourth electro-magnetic radiation(s) relative to the first electro-magnetic radiation(s). The laser radiation can be associated with the fourth radiation(s), and a wavelength of the laser radiation can be controlled by the spectral filtering caused by the actions by the first, second and third arrangements.