| 摘要 |
<p>PURPOSE:To eliminate positioning of a light receiving element for monitoring emitted light from semiconductor laser by providing an absorption layer to be optically coupled with active layers of the semiconductor laser between the active layers and a modulator and extracting outside electric charge generated by light absorbed from the absorption layer. CONSTITUTION:An absorption layer 15 to be optically coupled with active layers of semiconductor laser 2 is provided between the active layers and a modulator 4, while an electrode 21 which extracts electric charge generated by light absorbed from the absorption layer 15 is formed, thereby constituting a monitor unit 3. Thus a part of light output from the semiconductor 2 is absorbed by the absorption layer 15 of the monitor unit 3 and the electric charge generated by the absorption is made to flow outside, so that an output state of the semiconductor laser 2 is detected by the magnitude of the electric charge. It is not necessary to secure an installation space for a light receiving element, thereby miniaturizing a package.</p> |
