Transitions Of Nd3 Research Articles

The fluorescence of Nd3+ in lead borate and bismuth borate glasses with large stimulated emission cross section

The stimulated emission cross section σp for the 1060 nm transition of Nd3+ in lead borate and bismuth borate glasses has been determined from fluorescence measurements. The compositional dependence of σp, which has been evaluated using radiative transition probability, refractive index of the host glass, effective fluorescence linewidth, and position of the band, with PbO/Bi2O3 content is investigated. The σp values of the 1060 nm band of Nd3+ for lead borate and bismuth borate glasses are found to be in the range 2.6–5.7×10−20 cm2 at 298 K and 3.0–6.3×10−20 cm2 at 4.2 K. The σp values are comparatively large suggesting the possible utilization of these materials in laser applications.

The new phosphates Ca 9[formula omitted](PO 4) 7 ( M = Li, Na; Ln = rare earth, Y, Bi)

The new family of triple phosphates Ca 9MLn 2 3 (PO 4) 7 ( Ln = rare earth, Y, Bi; M = Li +, Na + has been synthesized and studied by X-ray powder diffraction, IR-spectroscopy, differential thermal analyses and luminescence. All compounds have the whitlockite-like structure (space group R3c). Cell parameters, IR and emission (Eu 3+) spectra are given. The luminescence properties of trivalent europium are analyzed in Ca 9NaEu 2 3 (PO 4) 7 and Ca 9LiEu 2 3 (PO 4) 7 at 290 K. The fluorescence lifetime of the 4F 3 2 − 4I 11 2 transition of Nd 3+ is reported for the solid solutions Ca 9Nd xGd 1 − x(PO 4) 7, Ca 3 − xNd 2x 3 (PO 4) 2 and Ca 9M(Nd xGd 1 − x) 2 3 (PO 4) 7 (M = Li, Na).

A comparative study of diode pumped microchip laser materials: Nd-doped YVO4, YOS, SFAP and SVAP

Abstract The lasing performance of the Nd-doped microchip laser host materials YVO4, YOS, SFAP and SVAP operating on the 1 μm transition in Nd is examined. With 0·5 W and 2 W laser diode array pump sources Nd:YVO4 remains the material of choice for this transition while both Nd:SFAP and Nd:YOS show promise, although higher doping concentrations are required. Pump-induced damage made Nd:SVAP unsuitable as a microchip laser material.

Absorption and luminescence spectroscopy of Nd 3+ and Er 3+ in a zinc borate glass

4ZnO · 3B 2O 3 glasses doped with Nd 3+ and Er 3+ were investigated by optical spectroscopy. Emission transition probabilities, radiative life-times and fluorescence branching ratios for several excited states of the Nd 3+ and Er 3+ ions were estimated from the room temperature absorption spectra. The stimulated emission cross sections σ p for the near infrared laser transitions of Nd 3+ and Er 3+ were obtained from laser-excited luminescence spectra. The values of σ p are comparable with those shown by glasses used in solid state laser applications.

Blue microchip laser fabricated from Nd:YAG and KNbO3

A Nd:YAG/KNbO(3) composite-material microchip laser has generated blue radiation at 473 nm with output powers of 1 mW when diode laser pumped and 9 mW when Ti:sapphire laser pumped. The fundamental radiation generated by the quasi-three-level (4)F(3/2)-(4)I(9/2) transition in Nd:YAG at 946 nm was frequency doubled in KNbO(3) angle cut to be type I critically phase matched at 45 degrees C. Despite the normally isotropic nature of Nd:YAG, the fundamental is emitted linearly polarized and orthogonal to the linearly polarized blue radiation.

Neodymium and Erbium Implanted Gan

AbstractStrong rare earth (RE) emissions from Nd and Er implanted into MOCVD grown GaN were observed through photoluminescence (PL) with below bandgap excitation from an Ar+laser. Three well resolved manifolds of 4f lines from the crystal-field split 4F3/2 → 4I9/2, 4F3/2 → 4I11/2, and 4F3/2 → 4I13/2 transitions of Nd3+ were observed at low temperature at ˜0.98, ˜1.14, and ˜1.46 μm, respectively. The Er implanted GaN showed both the 4I13/2 → 4I15/2 Er3+ transition at ˜1.54 μm and the 4I11/2 → 4I15/2 Er3+ transition at ˜1.00 μm. The Er luminescence at ˜1.54 μm and Nd luminescence at ˜1.1 μm persisted to room temperature. Both Er and Nd implanted samples showed increasing RE3+ signal as annealing temperature increased from 700 to 1000 °C. The growth of new 4f crystal-field split-lines in the ˜1.54 μm 4I13/2 → 4I15/2 manifold as annealing temperature was increased to 1000 °C suggests multiple Er3+ radiative centers.

Spectroscopic characterization of Nd3+ :BAMGAR crystal

A spectroscopic investigation is performed on Nd 3+ -doped Ba 0.25 Mg 2.75 Y 2 Ge 3 O 12 (BAMGAR), a garnet structured germanate crystal host. The Judd-Ofelt analysis is applied to the measured room temperature absorption spectrum to determine the radiative decay rates and branching ratios of transitions from the Nd 3+ 4 F 3/2 state to the 4 I J manifolds. The measured fluorescence lifetime of the 4 F 3/2 metastable state of Nd 3+ is 303 μs. The radiative lifetime of this state is, however, obtained as 311 μs. The broader absorption near 800 nm, longer fluorescence lifetime of 303 μs, and the larger branching ratio of 44% for the 4 F 3/2 → 4 I 9/2 transition in Nd 3+ :BAMGAR are significant improvements over Nd 3+ :YAG as a 0.94 μm laser material.

Transition frequency and temperature dependences of homogeneous width of Nd 3+ ion in silicate glass

The homogeneous width of the 4 F 3 2 (1) - 4 I 9 2 transition of Nd 3+ ions which were doped into pure silicate glass was measured by accumulated photon echoes between 1.6 and 44 K. The origin of the dephasing of the Nd 3+ ions is attributed to the configurational changes peculiar to glass which are often modeled by the two-level systems (TLSs) and the Raman process with low-frequency vibrational modes of silicate glass. Besides the TLS dephasing process, the Raman process with low-frequency modes has been found to be transition frequency dependent, and the homogeneous width is larger on the higher transition frequency side. These increases in the homogeneous width are attributed to the increase in the elastic field interaction and the electron-phonon interaction, respectively. The transition frequency dependence of the homogeneous width can be explained by taking the positions of the host ions and the TLSs into account.

Time resolved spectroscopy of laser output of Nd 3+ doped calcium, niobium, gallium garnet

Stimulated emission experiments in the 4 F 3 2 → 4 I 11 2 transition of Nd 3+ in Ca 3(GaNb) 3O 12 show that two laser lines are emitted simultaneously and both independently. These experiments show the behaviour of the laser emission from two distinguishable subsets of Nd 3+ sites. This behaviour has been modeled using a four-level spectral rate-equation laser model, assuming the existence of two kinds of Nd 3+ populations with different emission spectra and a homogeneous line broadening at each site. The model explains the measured laser spectrum as well as the time delay between the emission of both laser lines.

Room-temperature fluorozirconate glass fiber laser in the violet (412 nm)

Continuous oscillation on the (2)P(3/2) ? (4)I(11/2) transition of Nd(3+) in a f luorozirconate glass (ZBLAN) fiber at room temperature has been observed. When pumped at ~590 nm, a Nd:ZBLAN f iber 39 cm in length lases in the violet at 412 nm and produces ~0.5 mW of power for 320 mW of pump power and a cavity output coupling of 0.4%. The breadth of the laser's excitation spectrum is ~12 nm (581-593 nm).

Spectral Hole-Burning of Nd3+ Doped Germanosilicate Fiber

We report the observation of spectral hole-burning in the 4 I 9/2 → 4 F 3/2 transition of Nd 3+ in a germanosilicate fiber. The temperature dependence of holes was measured in the range of 1.3-3 K and a power law of T 1.2+/−0.1 was found

Optical properties of single crystals of gallium-substituted NYAB: Y1 –xNdx(Al1 –yGay)3(BO3)4

Flux-grown single crystals of non-linear neodymium-doped yttrium aluminium tetraborate (NYAB), substituted with gallium (NYAB-Ga), have been prepaRecl. The Judd-Ofelt theory has been applied to evaluate the intensity parameters (Ω2+Ω4, Ω6), radiative transition rates and branching ratios. The optical behaviour of NYAB-Ga crystals, containing 0.3 Ga has been investigated. The emission cross-sections for the 4F3/2→4I11/2 transition in Nd3+ have been calculated and compared with those in NYAB, with a view to developing new self-frequency-doubling materials.

Copper content and superconductivity of Nd 1.85Ce 0.15Cu 1+δO y and Sm 1.85Ce 0.15Cu 1+δO y

The superconducting transition of Nd 1.85Ce 0.15Cu 1+δO y and Sm 1.85Ce 0.15Cu 1+δO y samples was studied as a function of the Cu content through magnetic modulated microwave absorption and resistivity measurements. Superconducting transitions were observed only for samples with a Cu content 1+ δ ≥ 1.01. This Cu excess seems to be necessary in order to obtain superconductivity in the electron doped materials.

Ultraviolet (381 nm), room temperature laser in neodymium-doped fluorozirconate fibre

Lasing in the ultraviolet has been observed in neodymium-doped fluorozirconate glass (ZBLAN) fibres at room temperature. For a cavity output coupling of < 0.1%, 74 µW of power was obtained at 381 nm (4D3/2 → 4I11/2 transition of Nd3+) when a 45 cm long fibre was pumped with 275 mW at a wavelength of nominally 590 nm.

Spectral Properties of Nd3+-Doped RO·Na2O·Al2O3·P2O5 (R=Mg, Ca, Ba) Glass System

The dependence of spectral properties of the Nd3+-doped (45- x)RO· xNa2O·2.5Al2O3·52.5P2O5 (R=Mg, Ca, Ba, 0≤x ≤31, mol%) glasses on RO and on its substitution with Na2O was investigated. Absorption, fluorescence spectra and lifetimes were measured. Both the stimulated emission cross section and the spontaneous emission probability for the 4F3/2→4I11/2 transition of Nd3+ in glass were calculated. The results indicate that the effect of RO depends on its ionic field strength and that the substitution of RO with Na2O loosens the glass structure so as to lower the degree of disorder of the phosphate chain structure. A stimulated emission cross section as large as 4.2×10-20 cm2 and half-lifetime concentration as high as 8×1020 ions/cm3 were obtained.

Copper content and superconductivity of Nd 1.85Ce 0.15Cu 1+δO y

The superconducting transition of Nd 1.85Ce 0.15Cu 1+δO y samples was studied as a function of the Cu content and processing temperature through magnetic modulated microwave absorption and dc magnetization measurements. Differential thermal analysis and scanning electron microscopy observations show an indication of a small Cu nonstoichiometry with a maximum Cu excess in the T' structure, δ max ≲ 0.01. Superconducting transitions were observed only for samples with a Cu content 1+ δ ≥ 1.01. This Cu excess seems to be necessary in order to obtain superconductivity in the Nd-Ce-Cu-O system.

Accumulated photon echo in CaF2-YF3 : Nd3+ crystals

Accumulated photon echoes were used to measure 1–800 ps dephasing times (T2) for the4I9/2 →4G5/2,2G7/2 transition of Nd3+ ions located in two different symmetry sites in highly disordered CaF2-YF3 crystals. The temperature dependence of 1/(πT2) from 9–100 K is described by a single phonon absorption process.

Synchronously pumped optical parametric oscillators using all-solid-state pump lasers

We discuss recent research on synchronously pumped optical parametric oscillators, outlining some advantages that this technique has over Q-switched pulsed and cw modes of operation. We also describe synchronously pumped devices that use potassium titanyl phosphate and lithium triborate with pump lasers based on second-harmonic generation of the 1047-nm transition in Nd:YLF. Specific emphasis is placed on all-solid-state synchronous pumping of the parametric oscillators and the ability to achieve high efficiencies with relatively low average pump powers. Both doubly and singly resonant devices are discussed with respect to their relative operational merits. We demonstrate broad tuning ranges, from the visible into the IR, and simultaneous four-color operation of the lithium triborate devices with both mode-locked Q-switched and cw mode-locked pump sources.

Calorimetric study of the superconducting transition in Nd 1.85Ce 0.15CuO 4−δ

We report the first observation of a specific-heat anomaly at the superconducting transition temperature of high-quality Nd 1.85Ce 0.15CuO 4−δ ceramics with T c =24 K. The amplitude of the jump is ΔC/ T c ≅6±0.5 mJ/mole K 2. Application of a magnetic field H results in a broadening of the C p anomaly while the onset temperature remains field independent. We discuss the consistency of these results with previous magnetic and transport measurements.

Spectral hole-burning of Nd3+-doped heavy metal fluoride glasses

Abstract The first observation is reported of persistent spectral hole-burning in fluoride glasses. Measurements were made on the 4 I 9 2 → 4 F 3 2 transition of Nd3+_ in ZBLAN and BIGaZYT glasses, with neodymium concentrations from 0.05 to 2 wt%. The spectral holes were observed either in absorption, or in fluorescence excitation with detection at 1.05 μm. The holes were typically a few percent in depth and their amplitude decayed non-exponentially, reaching 50% in 1 h. At 1.4 K, the holes in both fluoride glasses had a width of 150 MHz, measured in a regime where the width was independent of burning power and fluence. This broadening is much larger than observed in crystalline systems and is ascribed to dephasing by thermally activated tunneling systems. The temperature dependence of the holewidth was almost linear from 1.4 to 8 K, and differs from that reported recently in a neodymium-doped silica fiber.