Abstract: A photodetector device includes: a plurality of light detector elements; and a plurality of filters, in which each filter of the plurality of filters is arranged in front of a light detection surface of a corresponding light detector element to filter incoming light incident on the light detection surface, and in which the plurality of filters are configured to filter at least two different wavelength bands, respectively, of the incoming light, and in which the at least two wavelength bands combine to span a predefined range of wavelengths, and in which each filter of the plurality of filters has a corresponding spectral sensitivity, and in which a sum of the spectral sensitivity curves of the plurality of filters over the predefined range of wavelengths is a constant value.

Abstract: An optical device (306) includes an internal cavity and an emitter (102) disposed in the internal cavity (210). The emitter is operable to emit a first light wave (220). The optical device also includes a detector (104) disposed in the internal cavity. The detector is operable to detect a second light wave (225) that is based on the first light wave. The second light wave is susceptible to being coupled with an undesired light wave (235) that is based on the first light wave. The optical device further includes an interference filter (310) disposed on the detector. The interference filter has a filter property that causes the interference filter to attenuate the interfering light wave.

Abstract: A filter assembly includes comprises an incident medium, a spacer, at least one dielectric filter and an exit medium. The spacer is arranged between the incident medium and the at least one dielectric filter such that the incident medium and the at least one dielectric filter are spaced apart by a working distance and thereby enclose a medium of lower index of refraction than the incident medium. The at least one dielectric filter is arranged on the exit medium.