声致发光: 红外受激辐射放大(IRaser)?(英文)

SONOLUMINESCENCE: IRASER?

声致发光（ＳＬ）以Ｐｌａｎｃｋ理论来处理是将空泡看作为微型可变调谐红外受激辐射放大，当空崩裂时将红外辐射转变为可见光子．在ＩＲａｓｅｒ腔内，红外辐射被吸收并再发射回到腔内，其时间间隔满足ＩＲａｓｅｒ壁间的半波边界条件，约为１飞秒量级．此时，空泡壁的Ｐｌａｎｃｋ能量的增量约为２０～１０μｅＶ量级，由于红外吸收相继累积达到可见光子能级，然后在约～１００ｐｓ量级时间内再发射，由此解释观察到皮秒脉冲间隔的声致发光．Ｐｌａｎｃｋ能量增量只能激发依附在ＩＲａｓｅｒ壁上的水分子或其他分子的转动模式，由此解释了为什么在声致发光谱中没有观察到无转动模式的惰性气体的谱线．在冰点时声致发光增加可由水的低蒸气压来解释．反之，在高温时ＳＬ熄灭．估计空泡中的平均可见光子数、功率和光子能量可以从单一崩裂的ＳＬ空泡作出合理的解释．

Sonoluminescence (SL) in the Planck theory treats the bubbles as miniature variable tuned infrared maser (IRasers) converting infrared radiation to visible photons as the bubble collapses. The interval of time, while the infrared radiation within the IRaser cavity is absorbed and reemitted back into the cavity, is shown to be of order^1 fs in order to satisfy half wave boundary conditions at the IRaser walls. In this time, the Planck energy of the bubble wall molecules increases in increments of order^10 μeV. Visible photon levels are reached by successive accumulation of infrared absorptions and reemissions over a time of order^100 ps, so as to explain the observed picosecond pulse durations  SL. 