Photoacoustic measurement device and laser light source

A photoacoustic measurement device comprising:

• a laser medium;
• an excitation unit that excites the laser medium;
• an optical resonator including a pair of mirrors that face each other with the laser medium interposed therebetween;
• a Q switch that is provided on an optical path of the optical resonator and changes optical loss of the optical resonator, according to a voltage applied, such that the optical loss of the optical resonator when a first voltage level is applied to the Q switch is more than the optical loss of the optical resonator when a second voltage level lower than the first voltage level is applied to the Q switch;
• a laser light source that is provided on an optical path of laser emission light and has an optical path shutter;
• an acoustic wave detection unit that, after light is emitted from the laser light source to a subject, detects a photoacoustic wave generated by the emission of the light;
• a photoacoustic signal processing unit that performs signal processing for the photoacoustic wave;
• and
• a control unit that performs control such that, in a first operation mode in which laser emission is performed, the optical path shutter transmits the light from the laser light source and the voltage applied to the Q switch is changed from the first voltage level to the second voltage level to emit pulsed laser light after the excitation unit excites the laser medium;
• and such that, in a second operation mode in which the laser emission is interrupted and waited for, the optical path shutter blocks the light from the laser light source and the second voltage level is applied to the Q switch.