PURPOSE: To make self-supporting and difficult to be come hot easily, by successively stacking two layers of an outer layer, consisting of a comparatively hard material and a thermal conduction layer consisting of a second material with excellent thermal conductivity, on the mandrel to form a wave guide.

CONSTITUTION: This optical waveguide consists of a device consisting of two layers of an outer layer 10 which is rigid for an waveguide and an inner layer 16 having thermal conductivity, the three layers of an outer layer 14 with rigidity, an intermediate layer having thermal conductivity and a thin inner layer 18 preventing corrosion at the surface of the waveguide while being inactive. The outer layer 14 desirable consists of nickel, and the next important characteristic is to use two layers, in order to give satisfactory thermal conductivity which removes heat, so as to prevent damage to structure. The thicker one is made from copper, and the thinner one made from copper is formed inside of the copper layer. On the other hand, the inactive layer 18 inside is made from gold for protection. Thereby a new waveguide structure, resisting high laser output, is produced simply and inexpensively.