Prism-dye laser

A simple continuously tunable laser-pumped dye laser is described. A dye solution in contact with a lateral face of a right-triangular 90° prism, adjacent to the 90° corner, is pumped by laser light incident on the lateral face opposite to the 90° corner. A standing-wave pump field is produced in the dye solution by the interference between the pump light that passes directly to the inner face in contact with the dye solution and the pump light internally reflected from the other lateral face adjacent to the 90° corner. The output wave-length is determined by the spatial periodicity of the standing-wave field and is easily varied by changing the angle of incidence between the pump-laser beam and the prism face.