An imaging apparatus includes an image sensor, an optical system, a control circuit, and a signal processing circuit. The image sensor includes a light-shielding film in which light-transmitting regions and light-shielding regions are alternately arranged in at least a first direction within a plane, a photodetector disposed opposite the light-shielding film, and an optically-coupled layer disposed between the light-shielding film and the photodetector. The optically-coupled layer includes a grating which generates a propagating light that propagates in the first direction and a transmitting light that transmits the optically-coupled layer when light of a predetermined wavelength enters the light-transmitting regions. The signal processing circuit extracts two different frames from frames included in a moving image acquired by the image sensor.

An electronic detection system includes an electronic device, a detector and a memory. The electronic device includes a circuit substrate, a plurality of photoelectric components, and a plurality of tunable current source circuits. Each photoelectric component has one or more peak emission wavelengths in response to a plurality of current values. The tunable current source circuits are disposed on the circuit substrate and electrically connected to the photoelectric components. The detector captures a feature value of a corresponding one of the photoelectric components. One or more lookup tables stored in the memory are based on the feature values and the current values of the photoelectric components. Each tunable current source circuit transmits an input current to a corresponding one of the photoelectric components in response to the lookup table(s) to perform a selected peak emission wavelength.

Disclosed is an illumination arrangement for providing at least one radiation beam for use as an illumination beam and/or reference beam in a metrology device. The illumination arrangement comprises at least one radiation beam modifier module operable to receive source illumination and output a modified radiation beam comprising a first beam component and a second beam component. Each radiation beam modifier module comprises at least one path length varying arrangement for controllably varying the optical path length of at least one of said first beam component and said second beam component, such that said first beam component and second beam component of said modified radiation beam comprise a respective different optical path length.

An electronic detection system includes an electronic device, a detector and a memory. The electronic device includes a circuit substrate, a plurality of photoelectric components, and a plurality of tunable current source circuits. Each photoelectric component has one or more peak emission wavelengths in response to a plurality of current values. The tunable current source circuits are disposed on the circuit substrate and electrically connected to the photoelectric components. The detector captures a feature value of a corresponding one of the photoelectric components. One or more lookup tables stored in the memory are based on the feature values and the current values of the photoelectric components. Each tunable current source circuit transmits an input current to a corresponding one of the photoelectric components in response to the lookup table(s) to perform a selected peak emission wavelength.