The observation of statistical absorption fluctuations of an inhomogeneously broadened optical transition in a glass is reported. Frequency modulation spectroscopy in a 10-ppm ${\mathrm{Nd}}^{3+}$ -doped-silica optical fiber has also revealed spectral holes that persist for days at 4.2 K. Homogeneous linewidths ${\ensuremath{\Gamma}}_{h}$ measured using hole burning and fluctuations are in good mutual agreement but are significantly larger than those inferred from photon echo decays in the same system. This difference confirms recent predictions of a time-dependent ${\ensuremath{\Gamma}}_{h}$(t) arising from the tunneling dynamics of the glass.The observation of statistical absorption fluctuations of an inhomogeneously broadened optical transition in a glass is reported. Frequency modulation spectroscopy in a 10-ppm ${\mathrm{Nd}}^{3+}$-doped-silica optical fiber has also revealed spectral holes that persist for days at 4.2 K. Homogeneous linewidths ${\ensuremath{\Gamma}}_{h}$ measured using hole burning and fluctuations are in good mutual agreement but are significantly larger than those inferred from photon echo decays in the same system. This difference confirms recent predictions of a time-dependent ${\ensuremath{\Gamma}}_{h}$(t) arising from the tunneling dynamics of the glass.

Physical Review LettersOct 23, 198921 citations

Laser Hole Burning Spectroscopy: A High Resolution Probe of Molecular Environments.

R. M. Macfarlane, Robert M. Shelby

Laser induced hole burning in optical absorption bands of low temperature solids has been investigated with emphasis on mechanisms for population hole burning, the interactions with the environment which limit the hole widths and the use of hole burning for ultra high resolution spectroscopy. Hole burning was observed in a wide range of solids including organic and organometallic molecules in crystals and rare earth ions in crystals and glasses. The mechanisms for hole burning also varied widely and a new mechanism involving optically induced nuclear spin flips of near neighbor nuclei was discovered. Examples of hole burning in new classes of materials are presented here for the first time, namely inorganic glasses (silicate glasses containing Nd(3+), Pr(3+) or Eu(3+)) and undoped stoichiometric compounds (e.g., EuP5O14). Hole recovery was used to determine nuclear spin lattice relaxation rates in praseodymium doped crystals. For allowed optical transitions (e.g., singlet states of zinc porphyrin, dibromoindigo and color centers in alkali halides) the hole widths at 2K are limited by population decay to approximately 50 MHz. For longer lived optical levels in crystalline materials, e.g., those containing rare earth ions, the hole widths are narrower (less than 10 MHz) and are limited by dynamical interactions with surrounding nuclei. In amorphous materials such as europium doped silicate glass, hole widths are much broader, being limited by low frequency tunneling motions. Hole burning measurements were complemented by time domain coherent transient (photon echo, and optical free decay) measurements of homogeneous linewidths which enabled us to measure optical resonances as narrow as 760 Hz in Eu(3+):Y2O3.Laser induced hole burning in optical absorption bands of low temperature solids has been investigated with emphasis on mechanisms for population hole burning, the interactions with the environment which limit the hole widths and the use of hole burning for ultra high resolution spectroscopy. Hole burning was observed in a wide range of solids including organic and organometallic molecules in crystals and rare earth ions in crystals and glasses. The mechanisms for hole burning also varied widely and a new mechanism involving optically induced nuclear spin flips of near neighbor nuclei was discovered. Examples of hole burning in new classes of materials are presented here for the first time, namely inorganic glasses (silicate glasses containing Nd(3+), Pr(3+) or Eu(3+)) and undoped stoichiometric compounds (e.g., EuP5O14). Hole recovery was used to determine nuclear spin lattice relaxation rates in praseodymium doped crystals. For allowed optical transitions (e.g., singlet states of zinc porphyrin, dibromoindigo and color centers in alkali halides) the hole widths at 2K are limited by population decay to approximately 50 MHz. For longer lived optical levels in crystalline materials, e.g., those containing rare earth ions, the hole widths are narrower (less than 10 MHz) and are limited by dynamical interactions with surrounding nuclei. In amorphous materials such as europium doped silicate glass, hole widths are much broader, being limited by low frequency tunneling motions. Hole burning measurements were complemented by time domain coherent transient (photon echo, and optical free decay) measurements of homogeneous linewidths which enabled us to measure optical resonances as narrow as 760 Hz in Eu(3+):Y2O3.

Final ReportJun 1, 19810 citations

Complex tunneling dynamics

Ciann‐Dong Yang

Chaos Solitons & FractalsJun 22, 200631 citations

The observation of statistical absorption fluctuations of an inhomogeneously broadened optical transition in a glass is reported. Frequency modulation spectroscopy in a 10-ppm

{\mathrm{Nd}}^{3+}

-doped-silica optical fiber has also revealed spectral holes that persist for days at 4.2 K. Homogeneous linewidths ${\ensuremath{\Gamma}}_{h}$ measured using hole burning and fluctuations are in good mutual agreement but are significantly larger than those inferred from photon echo decays in the same system. This difference confirms recent predictions of a time-dependent ${\ensuremath{\Gamma}}_{h}$(t) arising from the tunneling dynamics of the glass.