Spectroscopic Properties of Nd3+ in CaF2 (original) (raw)

Laser spectral dynamics of Nd^3+ in CaF_2–YF_3 crystals

Journal of the Optical Society of America B, 1999

A spectral and dynamic study of spontaneous and stimulated emission of Nd 3ϩ in yttrofluorite CaF 2 -YF 3 (5%) crystals proves the existence of two main sites for the rare-earth ion in these crystals. Flash-lamp-pumped laser experiments show the existence of two laser output lines, centered at 1054 and 1063 nm, which correspond to stimulated emissions from the two resolved Nd 3ϩ sites. The dependence of the time-resolved laser output energy and relative intensities of both lines on the pump energy suggests the existence of some kind of coupling between the two emissions produced by the stimulated-emission field itself. The ratio between the output energies at the two wavelengths was modeled as a simple rate-equation laser model that takes the stimulated-emission coupling into account.

Thermoluminescence spectra and X-ray luminescence spectra of CaF2-Nd single crystals

Journal of Materials Science, 1987

X-ray luminescence measurements are an important tool in the study of the optical properties of a fluorite system. In the case of CaF2-Nd the major emission under X-ray excitation is in the infrared region, which has been studied extensively. In this paper emission in the ultraviolet and visible range under X-ray excitation is reported. Thermoluminescence (TL) and TL spectra in the same region have also been measured. The similarities in the peak emission wavelengths in the two processes show that the emission centres involved are the same.

Strong coherent interaction of Nd 3+–Nd 3+ pair ions in CaF 2 crystal 1 The paper was presented at DPC'97. 1

Journal of Luminescence, 1999

Excited Kramers fine level splittings of Nd3+ pair (M) and quartet (N) clusters in CaF2 crystal have been found and investigated by using absorption spectroscopy and accumulated photon echo (APE) techniques. Absorption spectra on the 4I9/2→4G5/2 transition between Kramers states split into four lines with overall splitting ∼5 cm−1 (T=9 K, NdF3 concentration 0.1, 0.3 and 1 wt%). At the picosecond laser excitation of the M- and N-centers on the same transition the APE kinetics was observed to be strongly modulated with multiple coherent beatings on pico- and nano-second time scale. Fast Fourier Transform (FFT) of the APE kinetics decay shows that nearest-neighbour absorption lines splittings 0.9, 1.5 and 2.1 cm−1 (M-center) are clearly defined in FFT spectrum. Theoretical study revealed that in general case the electrostatic interionic coupling lifts completely the eightfold degeneracy of the excited level of a pair of similar ions. The selection rules for the forced electric-dipole, magnetic dipole and quadrupole intermultiplet transitions are stated. It is suggested that in the case of Nd3+–Nd3+ pair in CaF2 (M-center), the strong quadrupole–quadrupole coupling is responsible for the fine splitting of the excited 4I9/2×4G5/2 levels and leads to delocalization of the optical electrons within ion pair.

Stark level structure and oscillator strengths of Nd3+ ion in different fluoride single crystals

Journal of Alloys and Compounds, 2001

Optical properties of three fluoride single crystals (YF , LiLuF and KY F) doped with Nd ions have been studied. Low 3 4 3 1 0 21 temperature absorption spectra lead to the Stark energy level scheme up to 29 000 cm. From room temperature absorption 31 31 measurements and using the Judd-Ofelt theory, the V , V and V parameters have been obtained in the LiLuF :Nd and KY F :Nd 2 4 6 4 3 1 0 crystals and radiative lifetimes have been calculated.

Strong coherent interaction of Nd3+–Nd3+ pair ions in CaF2 crystal

Journal of Luminescence, 1999

Excited Kramers fine level splittings of Nd> pair (M) and quartet (N) clusters in CaF crystal have been found and investigated by using absorption spectroscopy and accumulated photon echo (APE) techniques. Absorption spectra on the I PG transition between Kramers states split into four lines with overall splitting &5 cm\ (¹"9 K, NdF concentration 0.1, 0.3 and 1 wt%). At the picosecond laser excitation of the M-and N-centers on the same transition the APE kinetics was observed to be strongly modulated with multiple coherent beatings on pico-and nano-second time scale. Fast Fourier Transform (FFT) of the APE kinetics decay shows that nearest-neighbour absorption lines splittings 0.9, 1.5 and 2.1 cm\ (M-center) are clearly defined in FFT spectrum. Theoretical study revealed that in general case the electrostatic interionic coupling lifts completely the eightfold degeneracy of the excited level of a pair of similar ions. The selection rules for the forced electric-dipole, magnetic dipole and quadrupole intermultiplet transitions are stated. It is suggested that in the case of Nd>-Nd> pair in CaF (M-center), the strong quadrupole-quadrupole coupling is responsible for the fine splitting of the excited I ;G levels and leads to delocalization of the optical electrons within ion pair.

Two types of additional absorption spectra in CaF2 crystals

Soviet Physics Journal, 1969

A study of two types of additional absorption spectra observed in colored CaF 2 crystals is reported. The spectral shape for the additively colored crystal is governed by the experimental conditions; during photochemical coloring, it depends on the thermal prehistory of the sample. In all cases, a spectrum consisting of bands at 370 and 560 nm appears in crystals having a band near 200 nm. An additional band appears at 560 nm in the Smakula spectrum at high-irradiation doses; there are three stages in the increase of this band with increasing dose. A similar dependence on the radiation dose is observed for the 560-nmband in synthesized CaF 2 crystals. It is suggested that this band is due to defects produced in the lattice during the irradiation.