In Single Bubble Sonoluminescence(SBSL) a bubble of gas is trapped in water by an externally applied  ultrasonic (f  > 15 kHz) field.  The acoustic field acts to expand and contract the bubble during each cycle.  When the acoustic field is forced to be large enough, the collapse can become so violent that light  (see the photograph below) is emitted! The main focus of our experiment concerns the nature of the light emitting mechanism which is not yet understood. We study the effects of mixing in different noble gases in the trapped bubble.  In this photograph, the bubble is illuminated by a laser beam for Mie scattering measurement.