Laser diode

摘要

A laser diode chip (110) is placed in the vicinity of the center of a sub-mount (120) under the condition that the distance (b) between an edge on an output side of the sub-mount (120) and the front face of the laser diode chip (110) meets the formula, (b)<(a)/tan(theta/2), wherein the (a) is the distance between the upper surface of the sub-mount (120) and the lower surface of an active layer (140) of the laser diode chip (110) and the theta is the angle of the spread in the vertical direction of the laser beam emitted from the active layer (140).