PROBLEM TO BE SOLVED: To provide a technique for performing a stable giant pulse oscillation by reducing the occurrence of prelasing in a laser device.SOLUTION: A subject information acquisition device comprises: two reflectors a laser resonator provided between the two reflectors and including a Q switch serving to determine a Q value based on a voltage applied thereto and an excitation part for causing the optical excitation of a laser medium. The subject information acquisition device also comprises: a detector for detecting prelasing light coming from one of the reflectors and a control part which determines a voltage value based on a result of detection by the detector and applies the voltage to the Q switch. The subject information acquisition device further comprises: an irradiation part for irradiating a subject with laser light output from one of the reflector a receiving part for receiving acoustic waves propagated from the subject based on the irradiation with the laser light and an acquisition part for acquiring information about the subject based on a result of receiving by the receiving part.COPYRIGHT: (C)2016,JPO&INPIT【課題】レーザー装置において、プレレージングの発生を低減して安定したジャイアントパルス発振を行う技術を提供する。【解決手段】二つの反射体と、二つの反射体の間に設けられ、印加される電圧に基づいてQ値を決定するQスイッチとを含むレーザー共振器と、レーザー媒質を光励起する励起部とを備える。さらに、反射体の一方から出るプレレージング光を検出する検出部と、検出部の検出結果に基づいて電圧の値を決定し、この電圧をQスイッチに印加する制御部とを備える。さらに、反射体の一方から出力するレーザー光を被検体に照射する照射部と、レーザー光の照射に基づいて被検体から伝播する音響波を受信する受信部と、受信部の受信結果に基づいて被検体についての情報を取得する取得部とを備える。【選択図】図4
