INFRARED LASER PULSE ENERGY DETECTOR BASED ON PHOTOACOUSTIC EFFECT

We report the photoacoustic response of a piezoelectric sensor that was irradiated with laser pulses of wavelength of 1064 nm and different energy emitted by an Nd:YAG laser. The measurement of laser pulse energy was done with a meter, Newport model 1936-R with pyroelectric sensor and the photoacoustic signals with a Tektronix oscilloscope, model DPO3054 of 500 MHz. Experimentally, we found a linear dependence between the intensity of the photoacoustic signal of the piezoelectric sensor and the energy of the laser pulse. The sensitivity of the photoacoustic response of the sensor was dependent on the protective plate. For aluminum and aluminum plates painted black were (6.52 ± 0.06)mV/mJ and (51.2 ± 1.5)mV/mJ respectively. It was concluded that this type of piezoelectric sensor is very sensitive to the energy changes of 1064 nm pulsed lasers, its response is directly proportional to the incident energy, it is suitable for energy measurements of lasers pulsed in real time and it is not seen affected by acoustic noises or lighting conditions of the laboratory.