Probe

1. A probe in which an optical member is fitted in a distal end of a tubular member that is insertable to a lumen, the probe being configured to irradiate a measurement object part in the lumen with light and to acquire measurement light radiated from the measurement object part, wherein the probe comprises:

a holding section including a space having an internal diameter smaller than an internal diameter of the tubular member is provided at the distal end of the tubular member;

a liquid ejection trench configured to connect the space and an outer periphery surface of the holding section is formed in the holding section;

an excitation light fiber configured to irradiate the measurement object part with excitation light;

a light receiving fiber configured to receive measurement light radiated from the measurement object part; and

a lens provided as the optical member, the lens being provided in front of the excitation light fiber and the light receiving fiber in such a manner as to face a distal end side of the tubular member,

wherein an axial end portion of at least one of the excitation light fiber and the light receiving fiber is disposed at a position corresponding to an opening part of the liquid ejection trench on the space side of the holding section.

2. The probe according to claim 1 , wherein one liquid ejection trench is formed in the holding section.

3. The probe according to claim 1 , wherein two or more liquid ejection trenches are formed in the holding section.

4. The probe according to claim 1 , wherein the liquid ejection trench is formed in a tapered form whose width increases or decreases from the space side toward the outer periphery surface of the holding section.

5. The probe according to claim 1 , wherein a tapered surface having a dent form whose depth increases toward an inside in a radial direction of the holding section is provided to a surface of the holding section which faces the measurement object part.

6. The probe according to claim 1 , wherein, in a bottom portion of the liquid ejection trench, a stepped groove whose depth increases toward a center portion in the width direction of the liquid ejection trench is continuously formed along an extending direction of the liquid ejection trench.

7. The probe according to claim 1 , wherein the liquid ejection trench has a cross-sectional shape cut out in a V-shape whose width decreases toward a bottom portion.

8. The probe according to claim 1 , wherein a liquid housing section in communication with the liquid ejection trench is formed in the holding section.

9. The probe according to claim 1 , wherein a protrusion and a recess are formed in a bottom surface of the liquid ejection trench.