Abstract: Adjustment of a tunable external-cavity laser is simplified by incorporating a mount that includes a base, a main body, a reflecting surface, a diffracting surface and a hinge coupling the main body to the base. The laser additionally includes a light source, a converging lens located to receive light from the light source, a tuning mirror and a pivoting arm on which the tuning mirror is mounted. The main body is bounded in part by two plane, external surfaces orthogonal to a common reference plane and angularly separated from one another by an angle. The reflecting surface has a spatial orientation defined by one of the external surfaces and is arranged to receive light from the lens. The diffracting surface has a spatial orientation defined by the other of the external surfaces, and diffracts light received from the reflecting surface towards the tuning mirror. The hinge is located opposite the angle and parallel to the reference plane.