Knowledge Bank

An external electric field up to $104$ volts/cm has been applied on the dye cell which forms the active medium in a laser cavity. The dye is pumped by a pulsed nitrogen laser. The material is Rhodamine 6G with a concentration of $ \sim 10^{-3}$ molar in methanol at room temperature. The spectra have no apparent shifts but rather broadenings. By measuring the second moment of the spectra of laser output, the broadening is found proportional to the square of the applied electric field. It is found that broadenings are measured to be $3.09\times 10-7cm-1/(v/cm)2$. If simple stark calculations are made assuming the previously measured dipole moment chnage of 8D on excitation, the observed broadening of laser output cannot be explained.