Provided are a filter array, a spectral detector including the filter array, and a spectrometer employing the spectral detector. The filter array may have a multi-array structure including a plurality of filter arrays. The filter array may include a first filter array having a first structure in which a plurality of first filters with different transmittance spectrums are arranged, and a second filter array having a second structure in which a plurality of second filters with different transmittance spectrums are arranged, the second filter array being arranged to at least partially overlap the first filter array at a first position relative to the first filter array so that the multi-arrangement type filter array has a first set of absorbance characteristics. The second filter array may be configurable to be arranged to at least partially overlap the first filter array at a second position relative to the first filter array so that the multi-arrangement type filter array has a second set of absorbance characteristics different from the first set of absorbance characteristics.

A method of assessment of renal function by monitoring a time-varying fluorescence signal emitted from a fluorescent agent from within a diffuse reflecting medium with time-varying optical properties is provided that includes using a renal monitoring system comprising at least one light source, at least one light detector, at least one optical filter, and at least one controller to provide a measurement data set comprising a plurality of measurement entries, each measurement data entry comprising at least two measurements obtained at one data acquisition time from a patient before and after administration of the fluorescent agent.

A light detection device includes a semiconductor substrate, a signal detection light receiving portion, and an infrared light receiving portion. First and second color filters cover the signal detection light receiving portion and the infrared light receiving portion, respectively. The first color filter passes therethrough visible light in a first wavelength range as well as infrared light. The second color filter passes therethrough visible light in a second wavelength range as well as infrared light. A third color filter covers the infrared light receiving portion. The third color filter passes therethrough visible light in a third wavelength range different from the second wavelength range as well as infrared light. An infrared cut filter covers the signal detection light receiving portion and has an opening in a region opposite to the infrared light receiving portion.

A polarization property image measurement device includes: a first radiation unit that radiates light beams in different polarization conditions onto a target object after subjecting the light beams to intensity modulation at frequencies different from one another; a light receiving unit including first photoelectric conversion units that photoelectrically convert the light beams having been radiated from the first radiation unit and scattered at the target object in correspondence to each of the different polarization conditions, and second photoelectric conversion units that photoelectrically convert visible light from the target object; and a processor that detects signals individually output from the first photoelectric conversion units at the different frequencies and differentiates each signal from other signals so as to determine an origin of the signal as one of the light beams; and creates an image of the target object based upon signals individually output from the second photoelectric conversion units.

A photodetector includes a semiconductor substrate; a light receiving part for signal detection and an infrared light receiving part which are formed in the semiconductor substrate and are covered at least by first color filters having a common color; and second color filters which overlap with the first color filters on the infrared light receiving part and are configured to block light in a wavelength range transmitting through the first color filters.

A method of monitoring a time-varying fluorescence signal emitted from a fluorescent agent from within a medium with time-varying optical properties is provided that includes providing a measurement data set that includes a plurality of measurement entries that include at least two measurements obtained from a patient before and after administration of the fluorescent agent. The measurements may include one or more of: a DR.sub.ex signal detected by an unfiltered light detector during illumination by excitatory-wavelength light from first region adjacent to the diffuse reflecting medium; a Flr signal detected by a filtered light detector during illumination by excitatory-wavelength light; and a DR.sub.em signal detected by the unfiltered light detector during illumination by emission-wavelength light. The method further includes identifying a post-agent administration portion of the measurement data set; and transforming each Flr signal to an IF signal representing a detected fluorescence intensity emitted solely by the fluorescent agent.

A device includes a first multi-element image sensor; a second multi-element image sensor; and a polarizing layer positioned between the first and second multi-element image sensors. A portion of light having a first polarization state incident on the device along a first direction is transmitted through the first image sensor, is transmitted through the polarizing layer, and is detected by the second image sensor, and light having a second polarization state orthogonal to the first polarization state incident on the device along the first direction is transmitted through the first image sensor, is blocked by the polarizing layer.

A photodetector includes a semiconductor substrate; a light receiving part for signal detection and an infrared light receiving part which are formed in the semiconductor substrate and are covered at least by first color filters having a common color; and second color filters which overlap with the first color filters on the infrared light receiving part and are configured to block light in a wavelength range transmitting through the first color filters.

A multi-point spectral system includes an imaging lens, an image capturing module and a multiwavelength filter (MWF) disposed between the imaging lens and the image capturing module. The MWF has a plurality of narrow-bandpass filter (NBPF) units arranged in an array, and each of the plurality of NBPF units has a respective predetermined central transmitted wavelength. The multi-point spectral system is provided to capture plural spectral images of a scene, which contain spectral or color information of the scene. The multi-point spectral system may utilize the information of the plural spectral images to recognize features revealed at the scene.

A light detection device includes a semiconductor substrate, a signal detection light receiving portion that is formed in the semiconductor substrate, an infrared light receiving portion that is formed in the semiconductor substrate, a first color filter that covers the signal detection light receiving portion and that has a first spectral characteristic such that the first color filter passes therethrough light in a first wavelength range within the wavelength range of visible light and in the wavelength range of infrared light, a second color filter that covers the infrared light receiving portion and that has a second spectral characteristic such that the second color filter passes therethrough light in a second wavelength range within the wavelength range of visible light and in the wavelength range of infrared light, a third color filter that covers the infrared light receiving portion and that has a third spectral characteristic such that the third color filter passes therethrough light in a third wavelength range different from the second wavelength range within the wavelength range of visible light and in the wavelength range of infrared light, and an infrared cut filter that covers the signal detection light receiving portion and that has an opening in a region opposite to the infrared light receiving portion.