Abstract: [Object] To provide a polarization independent optical isolator enabling downsizing of a Faraday element and a magnet. [Solving means] The polarization independent optical isolator comprises: a pair of wedge-shaped birefringent crystal plates (1, 2) provided in an optical path; and a Faraday element (30) made of a paramagnetic body and provided in the optical path between the wedge-shaped birefringent crystal plates. The pair of wedge-shaped birefringent crystal plates have inclined light-transmitting surfaces parallel to each other and non-inclined light-transmitting surfaces parallel to each other. The non-inclined light-transmitting surfaces are disposed to face the Faraday element.

Abstract: [Object] To provide a polarization independent optical isolator enabling downsizing of a Faraday element and a magnet. [Solving means] The polarization independent optical isolator comprises: a pair of wedge-shaped birefringent crystal plates (1, 2) provided in an optical path; and a Faraday element (30) made of a paramagnetic body and provided in the optical path between the wedge-shaped birefringent crystal plates. The pair of wedge-shaped birefringent crystal plates have inclined light-transmitting surfaces parallel to each other and non-inclined light-transmitting surfaces parallel to each other. The non-inclined light-transmitting surfaces are disposed to face the Faraday element.

Abstract: A composite lead frame in which an island formed with a greater diameter than that of a semiconductor device to be mounted is attached to a lead frame main body having leads being integrally protruded inward, the top ends of the leads are bonded with corresponding fine leads of the island at one ends thereof and lead terminals of the semiconductor device are connected respectively to the other ends of the corresponding fine leads, wherein the composite lead frame comprises an insulating sheet appended on one surface of the island and having the fine leads secured thereto being protruded outward and through holes disposed discretely passing through the insulating sheet and the island so that the wire bonding portions at the other ends of the fine leads are exposed.