Patent ID: 8345237

Claim:
An optical information analyzing device that measures optical information on specimens by irradiating single-mode irradiation light to the specimens, which are objects to be measured and are dispersed in a liquid flowing through a flow passage, the optical information analyzing device comprising: a flow cell that includes the flow passage; an introduction nozzle that introduces the liquid into the flow passage of the flow cell; an irradiating unit that irradiates irradiation light to the liquid flowing through the flow passage of the flow cell; a transmitted light receiving unit that is provided at a position directly facing the irradiating unit, with the flow cell interposed therebetween, receives transmitted light, which is the irradiation light irradiated from the irradiating unit and transmitted through the liquid, and detects the transmitted light as a transmitted light signal; and an analyzing unit that measures the optical information on the specimens on the basis of the transmitted light signal detected by the transmitted light receiving unit and analyzes the specimens, wherein the transmitted light receiving unit is disposed so that a light receiving surface substantially perpendicular to an optical axis faces the irradiating unit and the center of the light receiving surface is substantially aligned with an optical axis of the irradiating unit, wherein a diameter d″ of the light receiving surface of the transmitted light receiving unit and an irradiation diameter D of the irradiation light that is irradiated from the irradiating unit onto the light receiving surface of the transmitted light receiving unit satisfy a relational expression of “d″≦D”, wherein the transmitted light receiving unit includes an optical fiber that is disposed so that a light receiving surface substantially perpendicular to the optical axis faces the irradiating unit, wherein a core diameter d of the optical fiber and an irradiation diameter D of the irradiation light that is irradiated from the irradiating unit onto the light receiving surface of the optical fiber satisfy a relational expression of “d≦D”, and wherein a clad diameter d′ of the optical fiber and an outer irradiation diameter D′ of the irradiation light that is irradiated from the irradiating unit onto the light receiving surface of the optical fiber further satisfy a relational expression of “D′≦d′”.