Abstract: A superfinishing method of a tapered roller bearing, including the steps of: rotating an outer ring of the tapered roller bearing about a center axis thereof; inserting a straight-shaped superfinishing stone from a front face of outer ring; and slidingly contacting a leading end face of the superfinishing stone with a taper-shaped raceway surface formed in an inner peripheral surface of the outer ring to thereby superfinish the raceway surface. The superfinishing stone is inclined outwardly of the front face of outer ring with respect to a vertical line of the raceway surface.

Abstract: A spot size converter comprising an incident area of a first size, an exit area of a second size different from the first size, and side walls defining a light guide, wherein at least a part of side wall inclines from the width direction axis and the thickness direction axis of the incident area is provided. Thereby, it is able to regulate the divergence of the outgoing light, and to optically couple optical elements of different spot size with each other at a high-efficiency. Moreover, the semiconductor laser module and optical fiber laser device using such a spot size converter are provided.

Abstract: An optical fiber, having a fiber cladding and a fiber core doped with laser active material, is embedded in an optical waveguide core having a refractive index almost equal to that of the optical fiber cladding, and pumping light is guided, in a side pumping manner, from the semiconductor laser via the light-guiding section. The guided pumping light is absorbed by the laser active material, as it propagates and moves around in the optical waveguide core in a fixed direction. Because the optical waveguide core is ring-shaped and enclosed by the optical waveguide cladding having a low refractive index, the rest of the guided pumping light propagates and moves around in the optical waveguide core again. Therefore, a laser active material in the optical fiber core can be pumped efficiently.