Multipoint detection fiber sensor and insertion apparatus including multipoint detection fiber sensor

An insertion apparatus comprising:

• a flexible insertion section inserted into an insertion target;
• a plurality of sensing parts at a plurality of positions of the insertion section, the sensing parts being able to detect curve amounts respectively, the sensing parts being incorporated into a plurality of optical fibers arranged in an overall effective detection area that is a range in which the sensing parts detect curve amounts, each of the optical fibers including the sensing parts;
• a light source that supplies light to the optical fibers;
• and
• a light receiver that receives light emitted through the optical fibers to which light is supplied;
• wherein the optical fibers have light absorption characteristics whose absorption wavelength characteristics are respectively different in a predetermined wavelength region emitted from the light source,
• the light absorption characteristics include characteristic absorption bands, the number of the characteristic absorption bands being equal to or larger than that of the sensing parts, the characteristic absorption bands being wavelength ranges having different light absorption rates in the predetermined wavelength region;
• the supplied light from the light source includes wavelength components of the characteristic absorption bands;
• and
• the light receiver is configured to detect an amount of light of the characteristic absorption bands.