Disclosed herein an apparatus and method for estimating a phase retarder and method of manufacturing the phase retarder using the same. The apparatus includes: a polarization element configured to output an incident light as a linear polarization and to make the linear polarization incident onto a phase retarder to be tested; a polarization image acquisition module equipped with a plurality of polarized pixels receiving an emitting light that is output from the phase retarder, on which the linear polarization is incident, and configured to obtain a polarization image based on the emitting light that is modulated in the polarized pixels; and a processor configured to evaluate quality of the phase retarder based on uniformity of a brightness value between polarized pixels of the polarization image. The polarized pixels modulate the emitting light based on a plurality of transmission angles and detects the modulated emitting light.

Disclosed herein an apparatus and method for estimating a phase retarder and method of manufacturing the phase retarder using the same. The apparatus includes: a polarization element configured to output an incident light as a linear polarization and to make the linear polarization incident onto a phase retarder to be tested; a polarization image acquisition module equipped with a plurality of polarized pixels receiving an emitting light that is output from the phase retarder, on which the linear polarization is incident, and configured to obtain a polarization image based on the emitting light that is modulated in the polarized pixels; and a processor configured to evaluate quality of the phase retarder based on uniformity of a brightness value between polarized pixels of the polarization image. The polarized pixels modulate the emitting light based on a plurality of transmission angles and detects the modulated emitting light.

Methods and apparatus for producing images of the retina or fundus with improved quality and visualization of its features. This is accomplished by adjustment of specific pupil size, pupil position, detector pinhole size and wavelength parameters of the instrument to give improved image quality as described by a chosen image quality metric. Methods are less complex than adaptive optics and give an improved image in a region of interest and potentially over a larger field of view. Thus, it will be useful in instruments designed for the screening of retinal disease(s). The methodology is applicable to an individual's eye, on the basis of either the group that said individual falls into or measurements of the quality of their eye's optics. As described herein, the settings (including optimum pupil size, pupil position, detector pinhole size and/or wavelength for imaging) can be chosen to give improved the retinal image quality.

A device for measuring an aberration has an image sensor, projection optics for optically projecting onto the image sensor, an optical unit for influencing the optical projection onto the image sensor so that the result on the image sensor is a multiple image of a plurality of sub-images, wherein the optical unit has at least one region per sub-image, wherein the regions influence different lateral portions of a wavefront incident on the projection optics in different ways, and an evaluator configured to determine information relating to the aberration based on the multiple image.

A device for measuring an aberration has an image sensor, projection optics for optically projecting onto the image sensor, an optical unit for influencing the optical projection onto the image sensor so that the result on the image sensor is a multiple image of a plurality of sub-images, wherein the optical unit has at least one region per sub-image, wherein the regions influence different lateral portions of a wavefront incident on the projection optics in different ways, and an evaluator configured to determine information relating to the aberration based on the multiple image.

A light measurement apparatus includes a master laser, a slave laser, an illumination light pulse, and a signal-under-measurement generator. The master laser generates as an output a master laser light pulse, and the slave laser generates as an output a slave laser light pulse having a repetition frequency or a phase different from that of the master laser light pulse. The illumination light pulse generator receives the master laser light pulse and generates as an output an illumination light pulse, and the signal-under-measurement generator, at a point in time when receiving a light pulse under measurement obtained by illuminating the object under measurement with the illumination light pulse and further the slave laser light pulse, generates as an output a signal under measurement according to a power of the light pulse under measurement. The apparatus corrects an error in a measurement of the signal under measurement.

A light measurement apparatus includes a master laser, a slave laser, an illumination light pulse, and a signal-under-measurement generator. The master laser generates as an output a master laser light pulse, and the slave laser generates as an output a slave laser light pulse having a repetition frequency or a phase different from that of the master laser light pulse. The illumination light pulse generator receives the master laser light pulse and generates as an output an illumination light pulse, and the signal-under-measurement generator, at a point in time when receiving a light pulse under measurement obtained by illuminating the object under measurement with the illumination light pulse and further the slave laser light pulse, generates as an output a signal under measurement according to a power of the light pulse under measurement. The apparatus corrects an error in a measurement of the signal under measurement.

Various embodiments of the teachings herein include a method for determining a radiation intensity and/or a wavelength of a process light, wherein the melt pool underlying the process light can be generated by irradiating a metal material with an energy beam along a path, wherein the energy beam can be moved in accordance with a power profile along the path. The method may include: providing a power profile for a section of the path as an input variable for a machine learning model; training the model using historical and/or synthetic power profiles and associated historical or synthetic radiation intensities and/or wavelengths of the process light for the metal material; and determining the radiation intensity and/or the wavelength of the process light as an output variable of the model.

Various embodiments of the teachings herein include a method for determining a radiation intensity and/or a wavelength of a process light, wherein the melt pool underlying the process light can be generated by irradiating a metal material with an energy beam along a path, wherein the energy beam can be moved in accordance with a power profile along the path. The method may include: providing a power profile for a section of the path as an input variable for a machine learning model; training the model using historical and/or synthetic power profiles and associated historical or synthetic radiation intensities and/or wavelengths of the process light for the metal material; and determining the radiation intensity and/or the wavelength of the process light as an output variable of the model.

A laser wavelength detector includes first and second sensors having a common field of view. A filter having two or more monochromatic attenuation coefficients optically couples the second sensor to the field of view. The filter attenuates incident monochromatic laser illumination detected by the second sensor more heavily than incident monochromatic laser illumination detected by the first sensor such that wavelength of incident laser illumination can be identified according to a ratio of first and second sensor intensities.