Optical Properties Of Yb3 Research Articles

Continuous-wave and Q-switched microchip laser performance of Yb:Y_3Sc_2Al_3O_12 crystals

Optical properties of Yb:Y(3)Sc(2)Al(3)O(12) crystal were investigated and compared with those from Yb:YAG crystals. The broad absorption and emission spectra of Yb:Y(3)Sc(2)Al(3)O(12) show that this crystal is very suitable for laser-diode pumping and ultrafast laser pulse generation. Laser-diode pumped continuous-wave and passively Q-switched Yb:Y(3)Sc(2)Al(3)O(12) lasers with Cr(4+):YAG crystals as saturable absorber have been demonstrated for the first time. Continuous-wave output power of 1.12 W around 1032 nm (multi-longitudinal modes) was measured with an optical-to-optical efficiency of 30%. Laser pulses with pulse energy of over 31 microJ and pulse width of 2.5 ns were measured at repetition rate of over 12.7 kHz; a corresponding peak power of over 12 kW was obtained. The longitudinal mode selection by a thin plate of Cr(4+):YAG as an intracavity etalon was also observed in passively Q-switched Yb:Y(3)Sc(2)Al(2)O(12) microchip lasers.

Growth and optical properties of Yb3+-doped Ba3Y2(BO3)4 crystal

Yb3+:Ba3Y2(BO3)4 crystals with dimension of ∅20×30mm3 and few cracks have been grown by Czochralski method. Yb3+:Ba3Y2(BO3)4 crystal congruently melts at 1222.7°C. The strongest absorption band of Yb3+:Ba3Y2(BO3)4 is at 977nm with an absorption coefficient of 5.8cm−1 and FWHM of 8nm. The absorption cross-section of this peak is calculated to be 1.23×10−20cm2. The dominant feature of fluorescence spectrum is a broadband emission, extending from 925 to 1100nm. The emission cross-section is 8.05×10−20 cm2. The radiative lifetime and fluorescence lifetime are 0.587ms and 0.937ms, respectively.

Growth and optical properties of Yb3+-doped Sr3Gd2(BO3)4 crystal

A transparent Yb 3+ :Sr 3 Gd 2 (BO 3 ) 4 crystal with dimensions up to ∅10 × 22 mm 2 has been grown by the Czochralski method. The spectral properties have been investigated. The absorption cross-section σ a is 1.65 × 10 −20 cm 2 at 977 nm. The emission cross-section σ e is 0.94 × 10 −20 cm 2 at 1014 nm wavelength. The fluorescence lifetime is 1.18 ms at room temperature.

Growth and Optical Properties of YbxGd1‐xAl3(BO3)4 Single Crystals with Different Yb3+ Concentration.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Effect of heating on the optical properties of Yb3+-doped fibres and fibre lasers

The effect of heating on the optical properties of Yb3+-doped fibres is studied. It is shown that the lasing efficiency of fibre lasers depends on the fibre temperature, the type and extent of the effect being substantially dependent on the laser wavelength. It is proposed to use fibre heating to increase the efficiency of lasers emitting in the 1.15 — 1.2-μm region.

Thermal analysis and optical properties of Yb^3+/Er^3+-codoped oxyfluoride germanate glasses

Yb3+/Er3+-codoped Na2O–Al2O3–GeO2–PbO–PbF2 glasses that are suitable for use in fiber lasers, amplifiers, and waveguide devices have been fabricated and characterized. The density, refractive indices, optical absorptions, Judd–Ofelt parameters, and spontaneous-transition probabilities of the glasses have been measured and calculated. Intense and broad 1.53-μm infrared fluorescence and visible upconversion luminescence were observed under 976-nm diode laser excitation. For the 1.53-μm emission band, the full widths at the half-maximum increase and the peak wavelengths are blueshifted with an increase of PbF2. The stimulated-emission cross sections were calculated from the measured-absorption cross section according to the McCumber theory. The monotonically reduced emission cross section arises from the decreased refractive indices of glasses and the increased linewidth of the infrared fluorescence spectrum. For the upconversion emissions centered at 524, 547, and 660 nm, the emission intensity changes remarkably with PbF2 contents from 0 to 15 mol.%. The quadratic dependence of the green and red emissions on excitation power indicates that a two-photon absorption process occurs under the 976-nm excitation. The relatively long lifetimes of the Er3+ 4S3/2 and 4F9/2 levels for the NAGF3 glass gives rise to a much more intense upconversion emission.

Growth and optical properties of Yb3+-doped α-Ba3Y(BO3)3 crystal

Crystal of Yb3+-doped α-Ba3Y(BO3)3 has been grown by the Czochralski method. The spectroscopic characterizations have been investigated at room temperature. Yb3+:α-Ba3Y(BO3)3 crystal exhibits the broad absorption at 976nm with an FWHM of 5nm and a large overall spitting of 2F7/2 manifold (912cm−1). The absorption and emission cross-sections are 1.10×10−20cm2 at 976nm and 1.16×10−21cm2 at 1060nm, respectively. The fluorescence lifetime is 2.1ms.

Optical properties of ytterbium films in the far and the extreme ultraviolet.

The optical properties of thin film of ytterbium in the 53.6-183.6-nm spectral range are described. Yb film were deposited in ultrahigh-vacuum conditians, and their transmittance and reflectance were measured in situ. Transmittance measurements showed that Yb has a certain window of lower absorption at approximately 54-100 nm, which makes Yb an interesting material for filters in this difficult spectral range. The optical constants were obtained from transmittance measurements and from multiangle reflectance measurements. These are what we believe are the first reported optical measurements of fresh Yb films at wavelengths shorter than 107.8 nm. Aging studies were performed both under vacuum and in a desiccator and showed that the optical properties of Yb are strongly modified on aging.

Cooperative energy transfer in Yb3+–Tb3+ codoped silica sol-gel glasses

Optical properties of Yb3+–Tb3+ codoped silica sol-gel samples have been studied after the gel to glass transition. Different upconversion emissions have been observed under near infrared excitation at about 1 μm. The Tb3+ ions are excited by means of energy transfer processes from Yb3+ ions. The temporal evolution of the blue-green upconversion emissions coming from Tb3+ ions and their dependence on the excitation intensity at about 1 μm has been studied. The experimental results are in good agreement with a cooperative resonant energy transfer mechanism from Yb3+ ions. An efficient backtransfer process is observed from Tb3+ ions towards Yb3+ ions. The upconversion efficiency, which is limited by this backtransfer process, has been obtained and compared with other upconversion results in similar matrix.

Optical spectroscopy of Yb3+ions in CaxCd1−xF2

Optical properties of Yb 3+ ions in Ca x Cd 1-x F 2 (x = 0.30) crystals are investigated. Photoluminescence and absorption spectra of the intra-ion transitions were measured in a wide temperature range (4 - 300 K). It was found that position and shape of the Yb 3+ zero-phonon emission lines exhibit a noticeable temperature dependence, particularly at temperatures T < 50 K. In the same temperature limits, the position and the shape of the Yb 3+ zero-phonon absorption lines do not change significantly. It was found that the measured shift between energy of the emission and absorption zero-phonon lines is due to the efficient energy migration among the Yb 3+ ions.

Laser heated pedestal growth and optical properties of Yb 3+-doped LiNbO 3 single crystal fibers

The elaboration of Yb 3+-doped LiNbO 3:Sc 3+ and LiNbO 3:Mg 2+ single crystal fibers by the laser heated pedestal growth technique is reported. The ytterbium emission and absorption cross-sections are given. We show that it is possible to obtain the coincidence between the wavelength of phase-matching for second harmonic generation and the wavelength of laser emission by varying the host composition, in order to achieve a self-doubling laser material.

Electrical and Optical Properties of Yb, Er doped GaAs

ABSTRACTIn this paper we report results from electrical and optical measurements carried out on GaAs:Yb, Er.For GaAs:Yb electrical experiments such as photoconductivity (PC) and Photo Induced Current Transient Spectroscopy (PICTS) show that there is a level at 0.65eV related to Yb. This explains why no Yb3+ photoluminescence (PL) emission is detected, the recombination energy of the trapped excitons is too low (≈ 0.6eV) to excite the Yb3+ internal transition(≈ 1.24eV). We also present results on Er doped GaAs materials. From PL experiments we deduce an estimate of 10−19cm2 for the stimulated emission cross section. By PICTS and PC, we have evidenced a trap at 0.67eV related to Er ions in GaAs. And we think that in this case, the rare earth ions are excited via formation of bound excitons.