Abstract
The existence of the hysteresis loop between the sound pressure and the light intensity of single bubble sonoluminescence (SBSL) appearing at low air concentration is discussed. The light intensity rises spontaneously at the sound pressure of the starting of the sonoluminescence (SL). Pause time is given just after the SL turns off by the decrease in the sound pressure. The sound pressure is increased after the pause time. Then the relationship between the restarting sound pressure of the SL and the pause time is observed. The pause time is shorter, and the sound pressure at which the bubble starts luminescing shifts to the lower range. The effects of argon rectification are discussed using these observed results. It is shown that the observed results support the argon rectification hypothesis.