Element for optical isolator and optical isolator employing the same, together with semiconductor laser module employing the optical isolator element

An optical isolator element which is disposed in front of a laser array comprised of a plurality of laser active regions arranged in parallel, comprising

• at least one flat plate-shaped Faraday rotator and
• two or more flat plate-shaped polarizers which are alternately bonded together in a rectangular configuration in conformity to the arranged form of said laser active regions of said laser array, the at least one flat plate-shaped Faraday rotator and the two or more flat plate-shaped polarizers forming a laminate, wherein the outer peripheral surface of said element is cut such that, said outer peripheral surface is disposed parallel to an optical axis, incidence and emergence planes of said element are inclined at a predetermined angle with respect to a plane perpendicular to the Optical axis.