Patent ID: 7873092

Claim:
A laser diode comprising: a stack structure in which a first semiconductor layer of a first conduction type, a current confinement layer, an active layer, and a second semiconductor layer of a second conduction type are included in this order; at least a first photodetection layer device and a second photodetection layer device; wherein the first photodetection layer device has a first photodetection device contact layer of the second conduction type, a first photodetection layer device semiconductor layer of the first conduction type and a plurality of alternating light absorption layers and light non-absorption layers forming a multilayer semiconductor layer sandwiched between the first photodetection layer device contact layer and the first photodetection layer device semiconductor layer and the second photodetection layer device, absent of alternating light absorption layers and light non-absorption layers, has a device isolation layer, a second photodetection layer device photodetection layer and a second photodector layer device semiconductor layer of the second conduction type disposed between the device isolation layer and the second photodetection layer device photodetection layer with the first photodetection layer device disposed between the stack structure and the second photodetection layer device; and the plurality of light absorption layers provided on the corresponding position of antinodes or nodes of standing waves of light output from the active layer.