Generation of highly directional ultrasonic waves in sea

A theoretically and experimentally analysis was presented of ultrasonic wave generation in water by intensity modulated elliptical Gaussian laser beams. It was found that generated acoustic radiation is highly directional both in polar and azimuthally directions. Experimental results showed that over the frequency range of 5 to 20 kHz, there was an almost flat response with an average normalized phase sensitivity of -300 dB re 1/μPa and an average pressure sensitivity of -150.0 dB re rad/μPa. These results indicate that the present design offers the possibility of getting highly directional sound beams in a simple configuration.