Problem to be solved: to detect high speed photoacoustic wave by transient absorption photoacoustic effect.The observation deviceInduced optical system which irradiates induced light to a specimenObservation optical system which irradiates observation light to a specimenA detection portion for detecting a signal associated with the reaction of a sample by induced light and observation lightEquipped withDetection sectionThe first signal produced by the induced light and the observation light being irradiated onto the sample with simultaneous or predetermined time differenceThe difference between the induced light and the second signal caused by the irradiation of the specimen alone is detected.Diagram【課題】過渡吸収光音響効果による光音響波を高速に検出する。【解決手段】観察装置は、誘起光を試料に照射する誘起光学系と、観察光を試料に照射する観察光学系と、誘起光及び観察光が照射されたことによる試料の反応に伴う信号を検出する検出部と、を備え、検出部は、誘起光及び観察光が同時または所定の時間差をもって試料に照射されることにより生じる第１の信号と、誘起光及び観察光の少なくとも一方が単独で試料に照射されることにより生じる第２の信号との相違を検出する。【選択図】図１
