Systems, methods, and apparatuses for providing electromagnetic radiation sensing using sequential beam splitting. The apparatuses can include a micro-mirror chip having a plurality of light reflecting surfaces, an image sensor having an imaging surface, and a beamsplitter unit located between the micro-mirror chip and the image sensor. The beamsplitter unit includes a plurality of beamsplitters aligned along a horizontal axis that is parallel to the micro-mirror chip and the imaging surface. The beamsplitters implement the sequential beam splitting. Because of the structure of the beamsplitter unit, the height of the arrangement of the micro-mirror chip, the beamsplitter unit, and the image sensor is reduced such that the arrangement can fit within a mobile device. Within a mobile device, the apparatuses can be utilized for human detection, fire detection, gas detection, temperature measurements, environmental monitoring, energy saving, behavior analysis, surveillance, information gathering and for human-machine interfaces.

Methods, systems, and apparatus for a stray-light testing apparatus. In one aspect, the apparatus includes an optical assembly including a spatially extended light source and one or more optical elements arranged to direct light from the spatially extended light source along an optical path, a moveable frame supporting the optical assembly including one or more adjustable alignment features for guiding positioning of the stray-light testing apparatus relative to an onboard camera on a vehicle, and a shrouding mechanism attached to the frame and positioned on the frame such that, when the stray-light testing apparatus is aligned relative to the onboard camera on the vehicle and the optical path of the optical assembly is within the field of view of the onboard camera, ambient light exposure for the onboard camera is below a threshold.

Embodiments of the present invention include a backscatter reductant anamorphic beam sampler. The beam sampler can be implemented to measure a power of a reference beam generated by an electromagnetic radiation source in proportion to a power of a working beam. The beam sampler can provide astigmatic correction to a divergence of the working beam along one axis orthogonal to a direction of propagation. The beam sampler can further be implemented to prevent backscatter reentrant radiation from impinging upon a photodetector of the beam sampler resulting in a reduction of error and instability in an assay of the working beam.

A method and system for determining a photon statistics of a light source using an unbalanced beam-splitter is disclosed. The method includes collecting data for photon counts for a first output path and a second output path by a first detector and a second detector, respectively, for a first time period, a first power level, and a first characteristic and collecting data for photon counts for the first output path and the second output path by the first detector and the second detector, respectively, for a second time period, a second power level, and a second characteristic; and processing outputs of the first and the second detector to determine the photon statistics.

Techniques are provided to re-arrange the placement of a photodiode within an illumination system to achieve improved characteristics and reduced form factor. An illumination system includes a laser assembly, a MEMS mirror system, a beam combiner, and a photodiode. The laser assembly includes RGB lasers, and the MEMS mirror system redirects laser light produced by the RGB lasers to illuminate pixels in an image frame. The beam combiner combines the laser light. The photodiode is provided to determine a power output of the laser assembly by receiving and measuring some of the laser light. The photodiode may be beneficially positioned before or after collimating optics and/or the beam combiner.

Systems, methods, and apparatuses for providing on-board electromagnetic radiation sensing using beam splitting in a radiation sensing apparatus. The radiation sensing apparatuses can include a micro-mirror chip including a plurality of light reflecting surfaces. The apparatuses can also include an image sensor including an imaging surface. The apparatuses can also include a beamsplitter unit located between the micro-mirror chip and the image sensor. The beamsplitter unit can include a beamsplitter that includes a partially-reflective surface that is oblique to the imaging surface and the micro-mirror chip. The apparatuses can also include an enclosure configured to enclose at least the beamsplitter and a light source. With the apparatuses, the light source can be attached to a printed circuit board (PCB). Also, the enclosure can include an inner surface that has an angled reflective surface that is configured to reflect light from the light source in a direction towards the beamsplitter.

Methods for design and production of highly sensitive active and passive light detecting devices and systems. Orders of magnitude improvement in optical signal detection is made possible in high noise or low contrast scenes. The current invention creates a small spectral difference between two parts of a split light stream. When recombined, the altered light streams partially correlate, and that generates fall amplitude signal oscillation at a frequency that depends on the constituent spectrum. The full amplitude signals and spectrum dependent oscillation make signal discrimination much better than intensity-only methods. The effect of read noise, amplifier noise, dark current noise, and thermal noise due to photo detector shunt resistance, become less important when compared to light detection using prior art methods.

An apparatus and method of intersensor calibration including using a zero airmass response constant proportional to sensor absolute radiometric gain coefficients to monitor sensor radiometric stability. Tracking the ratio of zero airmass response constant values for similar bands between two sensors provides a parameter on a common radiometric scale for evaluating interoperability performance. The method includes imaging a solar signal using a mirror to create an image reference target, detecting the image reference target using a first sensor, generating a zero airmass response constant based on a ground sampling distance of the first sensor and an at-sensor radiance value, computing a radiometric gain coefficient of the first sensor using the zero airmass response constant, and comparing the radiometric gain coefficient of the first sensor to a radiometric gain coefficient of a second sensor to determine a gain ratio between the first sensor and second sensor.

A device for collecting light from one or more incident light beams includes a first surface extending in a first plane and a second surface spaced-apart from the first surface. The second surface extends in a second plane parallel to the first plane. At least one of the first surface and the second surface including an optical polish or forming a reflective mirror coating. An edge surface extends from the first surface to the second surface. At least a portion of the edge surface forms a reflective mirror. At least one structure is formed in the first surface. The structure extends inwardly into the device from the first surface. The structure is configured to redirect light from a light source directed at the first surface.

An example method includes recording dark images on an image sensor on-board an orbital vehicle during flight, which include a first image recorded before the orbital vehicle is over a predefined location on the Earth and a second image recorded after the orbital vehicle is over the predefined location; and recording third and fourth images on the image sensor during flight based on illumination from a light source that is on-board, with the third image being recorded before the orbital vehicle is over the predefined location and the fourth image being recorded after the orbital vehicle is over the predefined location. A fifth image is recorded on the image sensor during flight while the predefined location on the Earth is visible to the image sensor. The fifth image is based on light from a ground-based calibration system. The light source is calibrated during flight based on the five images.