MEASUREMENT OF ULTRAFAST DEPHASING TIME OF RUBY BY TRANSIENT GRATING WITH INCOHERENT LIGHT

Dephasing time T₂ of ruby in the absorption band ⁴T₂ has been measured for the first time using the method of transient grating with incoherent light. The population grating was induced in the material by two broad-band nanosecond pulses of a dye laser and probed by a Continuous Wave (CW) Ar⁺ laser. A t room temperature, T₂=0.04 ~0.08 ps was obtained when the sample was excited at λ=5640Å.