Abstract: The present invention includes a holding stay made of a heat conductive material that is the same as that of an isolator holder, the holding stay being in contact with a radiation stay made of a member having good thermal conductivity, the radiation stay being in contact with radiation fins extracted from the inside of the isolator holder through an external opening for extraction, columnar welded portions bond the holding stay and the isolator holder through openings for welding, the welded portions apply tensile force toward the isolator holder to the radiation stay via the holding stay, and the radiation stay presses the radiation fins by means of the above-described tensile force to be fixed to the isolator holder.

Abstract: The present invention includes a holding stay made of a heat conductive material that is the same as that of an isolator holder, the holding stay being in contact with a radiation stay made of a member having good thermal conductivity, the radiation stay being in contact with radiation fins extracted from the inside of the isolator holder through an external opening for extraction, columnar welded portions bond the holding stay and the isolator holder through openings for welding, the welded portions apply tensile force toward the isolator holder to the radiation stay via the holding stay, and the radiation stay presses the radiation fins by means of the above-described tensile force to be fixed to the isolator holder.

Abstract: A heat-dissipating structure for an optical isolator is capable of suppressing an increase in temperature caused by light absorption in a magnetic garnet crystalline film by radiation fins extending from the inside of an external heat conducting cover. The heat-dissipating structure for the optical isolator is formed by housing a magnetic garnet crystalline film (12), first and second heat conductive plates (6, 7, 8 and 9) and magnet 18 in the external heat conducting cover, placing the radiation fins (10 and 11) on the second heat conductive plate, attaching the first heat conductive plates (6 and 7) onto either side of the magnetic garnet crystalline film, arranging the second heat conductive plates (8 and 9) on the outer surface of the first heat conductive plates, and passing the radiation fins through guide openings (2a and 2b) in the isolator holder 2 to the outside of the external heat conductive cover from the extracting opening (3c) to be brought into contact with the outer grooves (4d and 5d).

Abstract: A heat-dissipating structure for an optical isolator is capable of suppressing an increase in temperature caused by light absorption in a magnetic garnet crystalline film by radiation fins extending from the inside of an external heat conducting cover. The heat-dissipating structure for the optical isolator is formed by housing a magnetic garnet crystalline film (12), first and second heat conductive plates (6, 7, 8 and 9) and magnet 18 in the external heat conducting cover, placing the radiation fins (10 and 11) on the second heat conductive plate, attaching the first heat conductive plates (6 and 7) onto either side of the magnetic garnet crystalline film, arranging the second heat conductive plates (8 and 9) on the outer surface of the first heat conductive plates, and passing the radiation fins through guide openings (2a and 2b) in the isolator holder 2 to the outside of the external heat conductive cover from the extracting opening (3c) to be brought into contact with the outer grooves (4d and 5d).

Abstract: An optical device incorporating an incident-side optical waveguide portion having an incident terminal port and an outgoing terminal port which are connected with a fiber array, and an outgoing-side optical waveguide portion having another outgoing terminal port. Between the incident-side and outgoing-side optical waveguide portions, there is disposed a wavelength division multiplexer for sending back an incident beam from the incident-side optical waveguide portion to the incident-side optical waveguide portion and permitting a part of the incident beam to pass therethrough. Between the wavelength division multiplexer and the outgoing-side optical waveguide portion, a polarization-independent type optical isolator is disposed. Between the wavelength division multiplexer and the incident-side optical waveguide portion, a first lens is disposed, and between the wavelength division multiplexer and the polarization-independent type optical isolator, a second lens is disposed.