Patent ID: 8509036

Claim:
A method of testing a plurality of laser diode units in a bar state, each of the laser diode units in which a laser diode that includes a first electrode and a second electrode formed on surfaces facing each other and that is mounted on a mounting surface of a submount such that the first electrode faces the mounting surface of the submount, comprising: a step of preparing a bar in which mounting areas each of which includes the laser diode unit formed thereon and dicing margins for separating the bar into the separate laser diode units are alternatively aligned along a longitudinal direction wherein a first pad electrically connected with the first electrode of the laser diode is disposed on the mounting surface of each of the mounting areas of the submounts and a second pad electrically connected to the first pad of either one of the mounting areas that are adjacent to the dicing margin is disposed on the mounting surface of each of the dicing margins of the submounts: a step of contacting sheet-shaped probes to the second electrode and the second pad at a slantwise angle with respect to the second electrode and the second pad, and pressing the probes to the second electrode and the second pad while deforming the probes; and a step of providing a potential difference between the second electrode and the second pad through the probes so that the laser diode emits laser light.