Techniques for facilitating non-uniformity correction calibrations are provided. In one example, an infrared imaging system includes an infrared imager and a logic device. The infrared imager is configured to capture a first set of infrared images of a reference object using a first integration time. The infrared imager is further configured to capture a second set of infrared images of the reference object using a second integration time different from the first integration time. The logic device is configured to determine a dark current correction map based on the second set of infrared images. The logic device is further configured to generate a non-uniformity correction map based on the dark current correction map. Related devices and methods are also provided.

Methods of sensor readout and calibration and circuits for performing the methods are disclosed. In some embodiments, the methods include driving an active sensor at a voltage. In some embodiments, the methods include use of a calibration sensor, and the circuits include the calibration sensor. In some embodiments, the methods include use of a calibration current source and circuits include the calibration current source. In some embodiments, a sensor circuit includes a Sigma-Delta ADC. In some embodiments, a column of sensors is readout using first and second readout circuits during a same row time.

Methods of sensor readout and calibration and circuits for performing the methods are disclosed. In some embodiments, the methods include driving an active sensor at a voltage. In some embodiments, the methods include use of a calibration sensor, and the circuits include the calibration sensor. In some embodiments, the methods include use of a calibration current source and circuits include the calibration current source. In some embodiments, a sensor circuit includes a Sigma-Delta ADC. In some embodiments, a column of sensors is readout using first and second readout circuits during a same row time.

A system comprising a display and an ambient light sensing module, the ambient light sensing module being located beneath the display. The display comprises an array of light emitting diodes and a first polarizer located above the display. The sensing module comprises a first sensor and a second sensor, a second polarizer being located above the second sensor.

The present invention provides a light sensor with dark current elimination. A dark current from a covered photodiode and a sensed current from a photodiode are respectively transformed to a dark voltage and a sensed voltage by a controlled integration circuit. A reverse capacitor receives the dark voltage and the sensed voltage to cancel out for each other, and outputs a corrected sensing voltage.

Aspects of the present disclosure include methods for determining photodetector gain for a plurality of photodetectors in a light detection system. Methods according to certain embodiments include applying a reference voltage to each photodetector in the light detection system, generating a reference data signal for each photodetector at the reference voltage, irradiating with a light source the photodetectors at a plurality of different applied voltages, generating output data signals for each photodetector at each of the plurality of different voltages and calculating gain of the photodetectors at each of the plurality of different applied voltages based on the output data signals for each photodetector at each applied voltage and the reference data signal. Systems (e.g., particle analyzers) having a light source and a light detection system that includes a plurality of photodetectors for practicing the subject methods are also described. Non-transitory computer readable storage medium are also provided.

A light sensor includes a semiconductor substrate supporting a number of pixels. Each pixel includes a photoconversion zone extending in the substrate between a front face and a back face of the substrate. An optical diffraction grating is arranged over the back face of the substrate at a position facing the photoconversion zone of the pixel. For at least two different pixels of the light sensor, the optical diffraction gratings have different pitches. Additionally, the optical grating of each pixel is surrounded by an opaque wall configured to absorb at operating wavelengths of the sensor.

The present invention is directed to electrical circuits and methods. According to a specific embodiment, the present invention provides a voltage compensation mechanism for one or more single-phone avalanche diodes (SPADs). A reference voltage is generated based at least on an operating voltage of the SPADs. The reference voltage is coupled to a charge pump that generates a compensation voltage for the diodes. There are other embodiments as well.

A system for dark current compensation in SPAD imagery is configurable to capture an image frame with the SPAD array and generate a temporally filtered image by performing a temporal filtering operation using the image frame and at least one preceding image frame. The at least one preceding image frame is captured by the SPAD array at a timepoint that temporally precedes a timepoint associated with the image frame. The system is also configurable to obtain a dark current image frame. The dark current image frame includes data indicating one or more SPAD pixels of the plurality of SPAD pixels that detect an avalanche event without detecting a corresponding photon. The system is also configurable to generate a dark current compensated image by performing a subtraction operation on the temporally filtered image or the image frame based on the dark current image frame.

Low-frequency Noise Cancellation Method for Optical Measurement Systems. The present disclosure provides a low frequency noise cancellation method for optical measurement system, An optical measurement system has a transmitter to drive an LED and a receiver connected to a photodiode. The LED driver will generate a pulse signal to drive the LED and act as the radiation source for the optical measurement. Consequently, the receiver will convert the received photo-diode current to a voltage signal. The signal will then be digitized by an ADC for further processing. A current DAC circuit IDAC is added at the front of the receiver and has the same timing control with the LED driver to cancel the DC portion of the received current.