[20p-S322-1~17] 1.6 Ultrasonics

[20p-S322-13] Time-resolved two-dimensional imaging of gigahertz surface acoustic waves generated at arbitrary frequencies with an asynchronous pulsed-optical probing

〇Osamu Matsuda¹, Hirofumi Shono¹, Shun Kato¹, Shogo Kaneko¹, Sylvain Mezil¹, Motonobu Tomoda¹, Oliver Wrigt¹ (1.Hokkaido Univ.)

Keywords:surface acoustic waves,time-resolved imaging,optical pulses

The time-resolved two-dimensional imaging of GHz surface acoustic waves so far utilizes optical pulses to generate acoustic waves and delayed optical pulses to detect the propagating acoustic waves. Thus the freedom of the generation has been greatly limited by the light pulse train, especially their repetition frequency. This paper deals a method to relief this limitation: the image of the acoustic waves generated by a signal source independent from the light pulse source is taken by the asynchronous laser pulse train. We present both the principle of the method and the experimental result for the acoustic waves generated by the inter-digital transducers driven by a radio frequency signal generator.