System and method for optical measurement of a target

摘要

The invention relates to a system and a method for optical measurement of a target, wherein the target is illuminated, either actively illuminated, reflecting ambient light, or self illuminating, and a measurement light beam received from the target or through it is detected. The prior art optical measurement systems generally include mechanical filter wheels and photomultiplier tubes, which cause the equipment to be expensive, large-sized and often not sufficiently accurate and stable. The objective of the invention is achieved with a solution, in which the illuminating light beam and/or measurement light beam is led through a Fabry-Perot interferometer or a set of two or more Fabry-Perot Interferometers, and the Fabry-Perot interferometer or a set of two or more Fabry-Perot Interferometers is controlled into different modes during the measurement of a single target. The invention can be applied in optical measurements where, for example, reflectance, absorption of fluorescence of the target is measured.

主权项

1. System for optical measurement of a target, the system comprising a detector for receiving measurement light beam from or through the target, and optionally a light source for illuminating the target with an illuminating light beam, wherein the system comprises at least one first Fabry-Perot interferometer within the path of the illuminating light beam and/or the path of the measurement light beam, wherein
at least one light transmission characteristic of each said first at least one Fabry-Perot interferometer is controllable, the system has first means for controlling each said first at least one Fabry-Perot interferometer into at least two modes with different values of said characteristic, and the first means for controlling are arranged to control each said first at least one Fabry-Perot interferometer into at least two modes with different values of said characteristic during a measurement of a single target, the first means for controlling each said first at least one Fabry-Perot interferometer are arranged to control each said first at least one Fabry-Perot interferometer successively into at least two different pass bands with different centre wavelengths in order to provide at least two successive measurements of a single target wherein different spectral components of illumination light and/or measurement light are passed by said first at least one Fabry-Perot interferometer during the at least two successive measurements, and one mode of the first at least one Fabry-Perot interferometer during a measurement of the target is a shutter mode, wherein the first at least one Fabry-Perot interferometer is controlled to block received light of the at least two different spectral components of the illumination light and/or the measurement light, in addition to said first at least one Fabry-Perot interferometer, the system has a further pass band filter, wherein the further pass band filter is located within the path of the illuminating light beam or the measurement light beam, wherein the further pass band filter is arranged to substantially block simultaneous transmission of light on more than one pass bands of said first at least one Fabry-Perot interferometer, and one mode of the first at least one Fabry-Perot interferometer during a measurement of a target is a shutter mode, wherein the first at least one Fabry-Perot interferometer is controlled to block received light of all wavelengths within the pass band of said further pass band filter and/or said fixed pass band filter.