PURPOSE: To enhance light condensing efficiency and to facilitate manufacturing, by forming the reflecting surface of a reflecting tube, which condenses light from an exciting lamp into a solid-state laser medium, in the shape of pseudo- elliptic tube, wherein flat planes are assembled.

CONSTITUTION: The reflecting surface of a reflecting tube 11 has a shape of a pseudo elliptic tube. The inner surface of the tube, which is the reflecting surface, is formed by assembling reflecting-surface forming flat planes 16 of small blocks 11a of a hexagonal body, which is formed by flat planes. A numeral 12 indicates an outer frame, in which the small blocks are coupled. A numeral 13 indicates an exciting lamp. A numeral 14 is a solid-state laser medium. A numeral 15 indicates excited light. After the small blocks 11a are coupled into the outer frame and the pseudo ellitic tube is formed, nickel and gold are plated on the inner surface of the pseudo elliptic tube. Mirrorsurface machining of the flat planes is remarkably easier than mirrorsurface machining of an elliptically curved surface or twin-elliptically-curved surface. Working for forming the pseudo-elliptic tube or twin-pseudo-elliptic tube by combining the flat planes is easier than working for shaping the elliptic tube or twin-elliptic tube.