A solid as a single-molecule trap: observation of spectral diffusion and hole-burning on the single-center level

Recent advances in absorption1 and fluorescence2 detection now allow high-quality measurement of the optical absorption spectrum of individual single-impurity molecules in both crystals and polymers at liquid-helium temperatures. Here, the solid may be viewed as a trap for the defect center similar to the well-known electromagnetic single-ion traps, except that Doppler and recoil effects are replaced by (static) inhomogeneous broadening and host-guest interactions. Most importantly, molecular rotation is absent because of steric effects at low temperatures.

© 1992 Optical Society of America