PROBLEM TO BE SOLVED: To provide a light emitting device that can use light efficiently with controlled optical properties.SOLUTION: A light emitting device 10 for emitting light with a controlled polarization state, has a light emitting element 1 that emits light, a polarizer 2 that allows the passage of polarization A in a polarization axis parallel to a predetermined reference direction, out of the light emitted by the light emitting element, and reflects polarization B in a polarization axis vertical to the reference direction, and a polarization axis conversion mechanism that changes the polarization axis of the polarization B to reflect it to the polarizer 2 side.SELECTED DRAWING: Figure 1【課題】 光学特性が制御された光を効率的に利用できる発光装置を提供すること。【解決手段】 偏光状態が制御された光を照射する発光装置10であって、光を発する発光素子1と、光のうち予め定められた基準方向と平行な偏光軸の偏光Aを透過し、当該基準方向と垂直な偏光軸の偏光Bを反射する偏光子2と、偏光Bの偏光軸を変えて偏光子2側に反射させる偏光軸変換機構と、を具備する。【選択図】 図1
