A phase transformation device may include a solid photosensitive material having a planar input facet and one or more reflective holographic phase masks (RHPMs) within a volume of the solid photosensitive material, where a particular one of the one or more RHPMs is formed as a periodic refractive index variation of the photosensitive material along a particular grating vector and further with a particular non-planar lateral phase profile, where at least one of a period of the refractive index variation along the grating vector or an orientation of the grating vector for each of the one or more RHPMs are arranged to reflect via Bragg diffraction light incident on the input facet that satisfies a Bragg condition, and where a phase distribution of the reflected light from a particular one of the one or more RHPMs is modified by the associated non-planar lateral phase profile.

In some implementations, an optical assembly comprises an optical cavity; one or more detectors; and an optical component having an input face and an output face configured to receive an input beam to the input face and to produce one or more primary output beams, and a plurality of secondary output beams from the output face, the secondary output beams resulting from multiple internal reflections within the optical component. At least one of the input face is not perpendicular to the input beam or the output face is not perpendicular to the one or more primary output beams. Each primary output beam is transmitted through the optical cavity perpendicular to at least one surface of the optical cavity, and directed to a respective one of the one or more detectors. Each detector is arranged to exclude at least a portion of each secondary output beam.

A method for measuring the optical quality of a given region of a glazing of a road or rail vehicle, the region being intended to be positioned in the optical path of an image-acquiring device, the measuring method being implemented by a measuring device including an emitter and a wavefront analyzer, the measuring method including emitting, with the emitter, a beam of light rays in the direction of the given region, analyzing, with the wavefront analyzer, the wavefront of the light rays transmitted by the given region, including generating a wavefront-error map, and determining, on the basis of the wavefront-error map, at least one optical-defect map, of any optical defects present in the region of the glazing.

A method for measuring the optical quality of a given region of a glazing of a road or rail vehicle, the region being intended to be positioned in the optical path of an image-acquiring device, the measuring method being implemented by a measuring device including an emitter and a wavefront analyzer, the measuring method including emitting, with the emitter, a beam of light rays in the direction of the given region, analyzing, with the wavefront analyzer, the wavefront of the light rays transmitted by the given region, including generating a wavefront-error map, and determining, on the basis of the wavefront-error map, at least one optical-defect map, of any optical defects present in the region of the glazing.

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.

A temperature compensation method for wavelength monitoring using spectrometers on photonic integrated chips and a related temperature-compensated wavelength monitoring device include an optical filter of the chip filters a source signal to provide at least one spectral reference line to a first spectrometer to detect thermal wavelength drifts thereof. At least one spectral line to be monitored is received by the same or another spectrometer of the chip to detect wavelength shifts thereof. The detected thermal drift of the reference line is compared to calibrated thermal drifts for the reference line which is associated with a calibrated thermal drift for the spectral response curve of the spectrometer receiving the spectral line to be monitored. A thermal drift rate for the response curve of the optical filter differs from a thermal drift rate for the response curve of the first spectrometer at least by an amount.

Methods and devices are described for performing an all-phase measurement of an ultra-fast laser pulse having a spectral range of greater than one octave. The ultra-fast laser pulse may be split into a first beam comprising a fundamental light with a wavelength λ.sub.0 and a second beam comprising a light with a wavelength 2λ.sub.0. The light with the wavelength 2λ.sub.0 may be frequency doubled to a light with a wavelength λ.sub.0 to generate an interference with the fundamental light. Fourier transform may be performed on an interference spectrum of the interference, and a relative envelope delay (RED) between the fundamental light and the frequency doubled light and a carrier envelope phase (CEP) may be acquired based on a result of the Fourier transform.

Methods and devices are described for performing an all-phase measurement of an ultra-fast laser pulse having a spectral range of greater than one octave. The ultra-fast laser pulse may be split into a first beam comprising a fundamental light with a wavelength λ.sub.0 and a second beam comprising a light with a wavelength 2λ.sub.0. The light with the wavelength 2λ.sub.0 may be frequency doubled to a light with a wavelength λ.sub.0 to generate an interference with the fundamental light. Fourier transform may be performed on an interference spectrum of the interference, and a relative envelope delay (RED) between the fundamental light and the frequency doubled light and a carrier envelope phase (CEP) may be acquired based on a result of the Fourier transform.

A device and method for phase imaging and element detection based on wavefront modulation are provided to overcome the disadvantages of an existing interferometry such as twin image elimination, limit resolution, under-sampling wavefront measurement, and multi-modal measurement. From the perspective of light field encoding, the accurate measurement to a complex amplitude of a light field to be measured is completely achieved by the iterative calculation, and at the same time, a twin image problem may be effectively eliminated, and it has the multi-modal (multi-wavelength) reconstruction ability. Theoretically, it is able to reach the diffraction limit resolution, may be widely used in phase imaging, optical element surface-type detection, polarization distribution measurement and the like, and it has a wide range of applications.

The present disclosure relates to a coherent aperture array system for steering an optical source beam. The system may have a plurality of spaced apart, steerable emitters each being able to be mechanically aimed at a remote target location to steer portions of the source beam toward the target location. Each steerable emitter has a subaperture controllable independently of a remaining reflective surface of its associated steerable emitter, to receive and reflect a subportion of the source beam portion. The subportion forms a sense beam which is reflected toward a phase imaging system. A separate reference beam is created from the portion of the source beam travelling toward each steerable emitter. Each sense beam and each reference beam are thus associated uniquely with one of the steerable emitters. A phase imaging system is responsive to each of the reference beams and the sense beams, and determines phase differences between the portions of the source beam being transmitted from each steerable emitter.