Robert Klieber

Hole-burning techniques for isolation and study of individual hyperfine transitions in inhomogeneously broadened solids demonstrated in Pr3+: Y2SiO5

A sequence of optical holeburning pulses is used to isolate transitions between hyperfine levels, which are initially buried within an inhomogeneously broadened absorption line. Using this technique selected transitions can be studied with no background absorption on other transitions. This makes it possible to directly study properties of the hyperfine transitions, e.g. transition strengths, and gives access to information that is difficult to obtain in standard holeburning spectroscopy, such as the ordering of hyperfine levels. The techniques introduced are applicable to absorbers in a solid with long-lived sublevels in the ground state and where the homogeneous linewidth and sublevel separations are smaller than the inhomogeneous broadening of the optical transition. In particular, this includes rare-earth ions doped into inorganic crystals and in the present work the techniques are used for spectroscopy of Pr3+ in Y2SiO5. New information on the hyperfine structure and relative transition strengths of the 3H4 - 1D2 hyperfine transitions in Pr3+:Y2SiO5 has been obtained from frequency resolved absorption measurements, in combination with coherent and incoherent driving of the transitions.

Nuclear quadrupole resonance of an electronically excited state from high-resolution hole-burning spectroscopy

Hole-burning spectroscopy can eliminate inhomogeneous broadening and thereby resolve the fine structure of optical transitions. In the case of rare-earth ions at low temperatures, the homogeneous linewidth is often small compared to the splittings due to nuclear-spin interactions. Hole-burning spectra can then be used to measure, e.g., nuclear quadrupole couplings. We have used this technique to study the hyperfine interaction of Pr in

Wave-vector-dependent exchange interaction and its relevance for the effective exciton mass in Cu2O

{\mathrm{Pr}}^{3+}:{\mathrm{YAlO}}_{3}

Time-resolved coherent double Raman detection of nuclear spin transitions

in the electronic ground state as well as in an electronically excited state. Using a stabilized ring dye laser system (linewidth

Correlating NQR transitions of ground and excited electronical states

l30\mathrm{kHz}),

Experimental demonstration of efficient and selective population transfer and qubit distillation in a rare-earth-metal-ion-doped crystal

we obtained hole-burning spectra that clearly resolved the excited-state interactions also. We show that the spectra depend sensitively on the relative orientation of the nuclear-spin quantization axes of the two electronic states. This allows us to decide between different values for the tensor orientation that have been published before.

Wave-Vector-Dependent Exciton Exchange Interaction

The wave-vector dependence of electron-hole exchange interaction is investigated. For the yellow 1S exciton in

High resolution spectroscopy of yellow 1S excitons in Cu2O

{\mathrm{Cu}}_{2}\mathrm{O}

Anisotropic effective exciton mass in Cu2O

the exchange is derived up to the order

K-dependent exchange interaction of quadrupole excitons in Cu2O

{k}^{2}