A method for determining the complex amplitude of the electromagnetic field associated with a scene, comprising a) capturing a plurality of images of the scene by means of a photographic camera, the images being focused in planes of focus arranged at different distances, wherein the camera comprises a lens of focal length F and a sensor arranged at a certain distance from the lens in its image space, taking at least one image pair from the plurality of images and determining the accumulated wavefront to the conjugate plane in the object space corresponding to the intermediate plane with respect to the planes of focus of the two images of the pair.

An apparatus and a method for correctly measuring a phase of an extreme ultraviolet (EUV) mask and a method of fabricating an EUV mask including the method are described. The apparatus for measuring the phase of the EUV mask includes an EUV light source configured to generate and output EUV light, at least one mirror configured to reflect the EUV light as reflected EUV light incident on an EUV mask to be measured, a mask stage on which the EUV mask is arranged, a detector configured to receive the EUV light reflected from the EUV mask, to obtain a two-dimensional (2D) image, and to measure reflectivity and diffraction efficiency of the EUV mask, and a processor configured to determine a phase of the EUV mask by using the reflectivity and diffraction efficiency of the EUV mask.

An apparatus and a method for correctly measuring a phase of an extreme ultraviolet (EUV) mask and a method of fabricating an EUV mask including the method are described. The apparatus for measuring the phase of the EUV mask includes an EUV light source configured to generate and output EUV light, at least one mirror configured to reflect the EUV light as reflected EUV light incident on an EUV mask to be measured, a mask stage on which the EUV mask is arranged, a detector configured to receive the EUV light reflected from the EUV mask, to obtain a two-dimensional (2D) image, and to measure reflectivity and diffraction efficiency of the EUV mask, and a processor configured to determine a phase of the EUV mask by using the reflectivity and diffraction efficiency of the EUV mask.

A color wheel phase detection method and system, and a projection device. The phase detection system comprises a color wheel (1), a color wheel motor (2) that drives the color wheel (1) to rotate, and a control circuit (3); the color wheel motor (2) is a three-phase motor, and the control circuit (3) comprises a three-phase driving circuit (31) for driving the color wheel motor (2) to operate. The phase detection system further comprises a phase detection device (4) for detecting the three-phase driving circuit (31); when detecting a preset phase, the phase detection device (4) sends a pulse signal to the control circuit (3) to implement color wheel phase detection. Therefore, the effects of low costs, high accuracy, and high reliability are achieved.

A color wheel phase detection method and system, and a projection device. The phase detection system comprises a color wheel (1), a color wheel motor (2) that drives the color wheel (1) to rotate, and a control circuit (3); the color wheel motor (2) is a three-phase motor, and the control circuit (3) comprises a three-phase driving circuit (31) for driving the color wheel motor (2) to operate. The phase detection system further comprises a phase detection device (4) for detecting the three-phase driving circuit (31); when detecting a preset phase, the phase detection device (4) sends a pulse signal to the control circuit (3) to implement color wheel phase detection. Therefore, the effects of low costs, high accuracy, and high reliability are achieved.

A spatial modulator is provided on a plane conjugate to a sample plane on which a sample is to be placed. The spatial modulator spatially modulates illumination light irradiated to the sample 2 or object light that has passed through or that has been reflected by the sample. A dark-field optical system removes the non-scattered light component of the first object light affected by the spatial light modulator so as to generate second object light. An image sensor records a hologram based on the second object light. A calculation processing apparatus combines complex amplitude information based on the modulation pattern supplied to the spatial light modulator and complex amplitude information based on the hologram with respect to the second object light so as to acquire a phase distribution originating from the sample.

An infrared wave front phase analyzer that can be used for measuring the wave front phase of laser diode (LD) beam to provide a quality characterization specification for the LD chips that are intended for use in optical sub-assemblies (OSAs), which has applications in optical transceiver manufacturing and fiber optic communications. An optical system mimics the OSA and includes optical elements to collect and collimate the LD output beam and to focus the collimated beam through a focus, which could otherwise be into the end of an optical fiber, before re-collimating the laser beam for evaluation by a wave front sensor. This imaging process measures a wave front of the output beam, yielding a quality specification of the LD for screening out the out-of-spec LDs in advance of their assembly within TOSA/BOSA manufacturing to lower production costs.

An infrared wave front phase analyzer that can be used for measuring the wave front phase of laser diode (LD) beam to provide a quality characterization specification for the LD chips that are intended for use in optical sub-assemblies (OSAs), which has applications in optical transceiver manufacturing and fiber optic communications. An optical system mimics the OSA and includes optical elements to collect and collimate the LD output beam and to focus the collimated beam through a focus, which could otherwise be into the end of an optical fiber, before re-collimating the laser beam for evaluation by a wave front sensor. This imaging process measures a wave front of the output beam, yielding a quality specification of the LD for screening out the out-of-spec LDs in advance of their assembly within TOSA/BOSA manufacturing to lower production costs.

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.

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.