Solid state laser device with a bi-cylindrical covexo-convex lens having selected radii of curvature to preferably pump a region of a laser medium

A solid-state laser device having a laser medium including an active material for emitting laser light when pumping light is irradiated thereon, reflecting means provided at the both sides of the laser medium having a common optical axis and composing a laser resonator, a semiconductor laser for emitting pumping light to be used for pumping the laser medium, of which the angle of radiation in a first plane including a line extending in the longitudinal direction of a light emitting portion of the semiconductor laser is different in magnitude from the angle of radiation in a second plane perpendicular to the first plane, and a focusing lens for receiving the pumping light emitted from the semiconductor laser and for focusing the received light on a region of the laser medium to be excited or pumped, wherein

• a bi-cylindrical convexo-convex lens, of which the both surfaces are cylindrical surfaces and curve outward, is employed as the focusing lens and wherein the radius of curvature of each cylindrical surface is selected such that a first region of the laser medium to be excited or pumped by a first component of the pumping light, which propagates on a plane parallel to the first plane, and a second component of the pumping light, which propagates on a plane parallel to the second plane, are contained in a predetermined region of the laser medium.