OPTICAL FIBER CABLE

摘要

PURPOSE:To reduce the diameter of an optical fiber by changing the contact quantity or contact position of the optical fiber and liquid having a suitable refractive index, thereby decreasing the exit angle from the optical fiber. CONSTITUTION:The prescribed liquid 13 is disposed in the spacing between the optical fiber 1 for guiding a laser beam and a tube 2 enclosing this fiber and is brought into contact with the optical fiber 1. In addition, the optical cable is so formed that the contact quantity or contact position of the liquid 13 and the optical fiber 1 can be varied as desired. The prescribed liquid 13 to be brought into contact with the optical fiber 1 acts as a clad and allows the light of the prescribed angle or above among the light rays propagating in the optical fiber 1 to leak to the outside of the optical fiber 1 so that the angle of the luminous flux emitted from the exit end is decreased. The diameter of the optical cable is thereby reduced.