| 摘要 |
PROBLEM TO BE SOLVED: To improve input resistance of an avalanche photo diode without significantly reducing a response speed of a monitor current.SOLUTION: The avalanche photo diode includes on a substrate 101: an n-type contact layer 102; an n-type field control layer 104; an avalanche multiplication layer 105; a p-type field control layer 106; a first light absorption layer 107; a second light absorption layer 109; and a p-type contact layer 110. A barrier layer 108 is provided between the first light absorption layer 107 and the second light absorption layer 109. The barrier layer 108 forms a barrier against electrons on a conduction band side from the second light absorption layer 109 to the first light absorption layer 107. |
