Patent ID: 7551817

Claim:
An optical probe comprising a tubular outer envelope, an optical fiber which is disposed in the direction of axis of the outer envelope inside the outer envelope, a light projecting means which collects light emitted from the front end of the optical fiber and projects it on a body-to-be-scanned disposed externally of the outer envelope, a partition member which partitions the space within the tubular outer envelope into an optical path area and a non-optical path area, wherein the optical path area includes the optical path of the light projected from the light projecting means and is comprised of the space between the tubular outer envelope and the light projecting means, wherein the non-optical path area is comprised of the space between the tubular outer envelope and at least a portion of the optical fiber; wherein a liquid layer is formed in the non-optical path area, and wherein a liquid having a high transmittance to the wavelength of the light is filled in the optical-path-area.