Patent ID: 7957002

Claim:
An optical measurement apparatus in which an illuminating light is irradiated to a sample in order to measure optical information of the sample dispersed in a liquid flowing through a flow passage, wherein a transparent member is arranged in an interface between an end face of an optical waveguide guiding the illuminating light generated by a light source and a wall face of the flow passage, wherein the transparent member comprises glass, wherein a wall face to the flow passage side of the transparent member directly contacts with the flow passage, wherein the refractive index matching agent placed in the interface between the end face of the optical waveguide and the transparent member comprises a low-viscosity refractive index matching agent, and a high-viscosity refractive index matching agent is placed surrounding the low-viscosity refractive index matching agent, wherein the optical waveguide is supported movably along an axis direction of the optical waveguide, a first direction perpendicular to the axis direction of the optical waveguide, and a second direction respectively perpendicular to the axis direction of the optical waveguide and the first direction.