Abstract: An optical device having: an optical fiber body; a ferrule which surrounds the above described optical fiber body and to which a recess that crosses a coreless fiber within the above described optical fiber has been provided; and an optical element which is provided within the recess in said ferrule, is provided with a protective member for protecting the above described recess, and the protective member has a restriction means for physically restricting the rotation of the optical device around the optical axis.

Abstract: An optical device having: an optical fiber body; a ferrule which surrounds the above described optical fiber body and to which a recess that crosses a coreless fiber within the above described optical fiber has been provided; and an optical element which is provided within the recess in said ferrule, is provided with a protective member for protecting the above described recess, and the protective member has a restriction means for physically restricting the rotation of the optical device around the optical axis.

Abstract: To provide a fabricating method of an optical communication part in which an optical element is fixed within a hollow holder, including the step of fixing an optical element by holding the optical element in a hollow portion of a holding portion of a metal made holder and calking a portion of the holder; wherein, the step includes calking the holder by heating the holder to a temperature higher than a operating temperature or cooling the holder to a temperature lower than the operating temperature depending on whether or not a thermal expansion coefficient of the holder is larger or smaller than that of the optical element. When the thermal expansion coefficient of the holder is larger than that of the optical element, and a heating temperature in calking is set within the range of 85° C. to 95° C., while when the thermal expansion coefficient of the holder is larger than that of the optical element the cooling temperature of the holder upon the calking is set within the range of −50° C.

Abstract: To provide a fabricating method of an optical communication part in which an optical element is fixed within a hollow holder, including the step of fixing an optical element by holding the optical element in a hollow portion of a holding portion of a metal made holder and calking a portion of the holder; wherein, the step includes calking the holder by heating the holder to a temperature higher than a operating temperature or cooling the holder to a temperature lower than the operating temperature depending on whether or not a thermal expansion coefficient of the holder is larger or smaller than that of the optical element. When the thermal expansion coefficient of the holder is larger than that of the optical element, and a heating temperature in calking is set within the range of 85° C. to 95° C., while when the thermal expansion coefficient of the holder is larger than that of the optical element the cooling temperature of the holder upon the calking is set within the range of −50° C.

Abstract: An electrochemical stain prevention apparatus of a submerged structure comprising a submerged structure of which at least the stain prevention surface is formed of a conductive film that does not generate chlorine even by applying a potential of 5 V vs. SCE or less, a counter electrode located so as not to contact with the submerged structure, and a power supply unit for passing a direct current through the submerged structure having the conductive film formed thereon and the counter electrode. Aquatic organisms adhered to the surface of the conductive film can effectively be controlled by applying a potential of from 0.1 to 5 V vs. SCE to the submerged structure of such a stain prevention apparatus without generating chlorine. A potential applied to the conductive film of the submerged structure can be controlled with good accuracy by disposing a reference electrode between the submerged structure and the counter electrode.