Subwavelength resolution in a transmission acoustic microscope configuration using fiber-tip sensors

Subwavelength resolution in a transmission acoustic microscope configuratio n is demonstrated using optical fiber-tip sensors as small-sized acoustic p robes. A slit with a width of 1/20 of the acoustic wavelength Lambda repres enting the object was detected with a lateral resolution of the outer fiber diameter which was approximate to 1/10 Lambda, and with a proper signal-to -noise ratio. Fiber preparation techniques may raise the resolution to the fiber core dimensions, and simultaneous detection of an acoustic and an opt ical image is proposed. (C) 1999 American Institute of Physics. [S0003- 695 1(99)00937-7].