The subject of the present disclosure is to enhance spectral characteristics.

The present disclosure relates to an optical sensor and an electronic apparatus. The optical sensor includes: multiple optical receivers, multiple color filters covering light receiving surfaces of the multiple optical receivers, and a multi-layer filter layered on the multiple color filters. The multiple color filters include a red color filter, a green color filter and a blue color filter. The multi-layer filter includes a first transmission wavelength region allowing transmission of a portion of the transmission wavelength regions of the green color filter and the blue color filter, and a second transmission wavelength region allowing transmission of a portion of the transmission wavelength region of the red color filter.

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 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 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 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 light-receiving element, comprising a plurality of photodiodes formed by stacking in this sequence, a lower reflection mirror, a resonator including a photoelectric conversion layer, and an upper reflection mirror on a semiconductor substrate, wherein the plurality of photodiodes share the semiconductor substrate and the lower reflection mirror, the plurality of photodiodes includes a first photodiode having a resonance wavelength 1 and a second photodiode having a resonance wavelength 2 that is larger than the resonance wavelength 1, and a reflectance of the lower reflection mirror has a first peak corresponding to the resonance wavelength 1 and a second peak corresponding to the resonance wavelength 2.

A sensor head is provided. In any of the various aspects of the invention, the sensor head has a housing enclosing at least two light sources configured to deliver light to a patient and comprising a blue LED first light source that delivers light at an excitatory wavelength and a green LED second light source, and at least one light detector configured to detect light at an emission wavelength from the patient. The sensor is useful for non-invasive monitoring of fluorescent tracers agents.

A sensor head is provided comprising a housing enclosing at least two light sources configured to deliver light to a patient and comprising a blue LED first light source that delivers light at an excitatory wavelength and a green LED second light source, and at least one light detector configured to detect light at an emission wavelength from the patient. The sensor is useful for non-invasive monitoring of fluorescent tracers agents.

An optical sensor includes a light receiving unit and a calculating unit. The light receiving unit includes a plurality of light receiving elements and a plurality of color filters. The plurality of light receiving elements include a first light receiving element and a second light receiving element through which a photocurrent flows when receiving light. The plurality of color filters include a yellow filter that covers a light receiving surface of the first light receiving element and a red filter that covers a light receiving surface of the second light receiving element. The calculating unit calculates an intensity of a yellow wavelength band based on a difference between a first output signal obtained from the photocurrent of the first light receiving element and a second output signal obtained from the photocurrent of the second light receiving element.

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.