纳米AlP/SiO_2中激光超声信号功率谱研究

Power spectrum of laser generated ultrasound in nano-structured AlP/SiO_2

对压电薄膜换能器检测的纳米AlP/SiO2 中激光超声信号的功率谱进行了研究 .结果表明 ,当激光功率密度约等于 9W /cm2 时 ,纳米AlP/SiO2 的声信号功率谱主要在 0～ 2 2MHz范围内 ,而常规玻璃 (SiO2 )在 0～ 1 0MHz之间 .相同激光能量照射下 。

By using Laser_PVDF the ultrasound power spectrum in nano_AlP/SiO 2 system are studied. The results show that with the same pulsed laser energy (9 W/cm 2), the power spectrum band width in nano_AlP/SiO 2 is larger than that in glass SiO 2, the former being from 0～22 MHz, the latter being from 0～10 MHz and the average power in nano_AlP/SiO 2 is larger than in glass SiO 2, too, and they are caused by the random absorption because of nano_particle space and dimension distribution, the effect of optical penetration respectively.