Sonoluminescence from an isolated bubble on a solid surface

Measurements of sonoluminescence from isolated cavities that spontaneously form on solid objects in a fluid-filled acoustic resonator are reported. The subnanosecond light flashes have a smooth ultraviolet spectrum similar to that from single bubbles, although with organic liquids low intensity Swan lines ride on the continuum. The hemispherical cavities reach maximum radii about five times larger than are realized in sonoluminescence from single bubbles. The sonoluminescence intensity continues to increase as the liquids are cooled to temperatures as low as 160 K.