LIGHT-EMITTING DEVICE AND LIGHT TRANSMISSION DEVICE

PROBLEM TO BE SOLVED: To provide a light-emitting device which enables the monitoring of a quantity of emission light in a light feedback part even in the case of using a light-emitting element of a light feedback type, and a light transmission device.SOLUTION: A light-emitting device comprises: a semiconductor layer including a light-emitting region 32 which generates modulation light Lo subjected to modulation by a signal Vpp, and a feedback region 34 arranged to be able to switch between a feedback mode for feeding a part of light generated in the light-emitting region 32 back to the light-emitting region 32 and a monitoring mode for monitoring a light quantity of light generated in the light-emitting region 32; and a control part which sets the feedback region 34 to the feedback mode and switches the feedback region 34 to the monitoring mode in at least part of a period without the signal Vpp in the case of generating modulated light Lo in the light-emitting region 32.SELECTED DRAWING: Figure 1 【課題】光帰還型の発光素子を用いた場合でも、光帰還部で発光光量のモニタが可能な発光装置、光伝送装置を提供すること。【解決手段】信号Ｖｐｐで変調された変調光Ｌｏを発生させる発光領域３２、及び発光領域３２で発生した光の一部を発光領域３２に帰還する帰還モードと発光領域３２で発生した光の光量をモニタするモニタモードとが切り替え可能とされた帰還領域３４を含む半導体層と、発光領域３２で変調光Ｌｏを発生させる場合には帰還領域３４を帰還モードに設定するとともに、信号Ｖｐｐのない期間の少なくとも一部の期間で帰還領域３４をモニタモードに切り替える制御部と、を備えた。【選択図】図１