A surface plasmon laser incorporates a metal layer, an additional medium layer given on the metal layer, and a round structure segment in which a murmuring exhibition mode is created in which surface plasmon light is produced because of surface plasmon reverberation on a connection point with the metal layer pivots along a circle, and a twisted piece framed to yield a piece of laser light created in the round structure part of the addition medium layer. We consider a thin layer of an n-type semiconductor sandwiched between a metal and a p-type semiconductor, and the p-n intersection is forward-one-sided. The mode design of the SPW, engendering along the metal surface, stretches out up to the p-n intersection, where it incites electron-opening recombination and gets intensified. The optical increase of the SPW laser can be made practically identical to that of a diode laser by lessening the thickness of the sandwich layer.