978 resultados para -Er^3
Resumo:
J-OEr_(3x)~(3+):Y_(3-3x)A_5O_(12)Er_x~(3+)Yb_(1-x)P_5O_(14)Er~(3+)_
Resumo:
The mechanism of the Yb(3+)-->Er(3+) energy transfer as a function of the donor and the acceptor concentration was investigated in Yb(3+)-Er(3+) codoped fluorozirconate glass. The luminescence decay curves were measured and analyzed by monitoring the Er(3+)((4)I(11/2)) fluorescence induced by the Yb(3+)((2)F(5/2)) excitation. The energy transfer microparameters were determined and used to estimate the Yb-Er transfer rate of an energy transfer process assisted by excitation migration among donors state (diffusion model). The experimental transfer rates were determined from the best fitting of the acceptor luminescence decay obtained using a theoretical approach analog to that one used in the Inokuti-Hirayama model for the donor luminescence decay. The obtained values of transfer parameter gamma [gamma(exp)] were always higher than that predicted by the Inokuti-Hirayama model. Also, the experimental transfer rate, gamma(2)(exp), was observed to be higher than the transfer rate predicted by the migration model. Assuming a random distribution among excited donors at the initial time (t=0) and that a fast excitation migration, which occurs in a very short time (t<gamma(-2)), reducing the mean distance between donor (excited) and acceptor, all the observed results could be explained. (C) 2003 American Institute of Physics.
Resumo:
70SiO(2)-30HfO(2) planar waveguides, doped with Er(3+) concentrations ranging from 0.3 to 1 mol %, were prepared by sol-gel route, using dip-coating deposition on silica glass substrates. The waveguides show high densification degree, effective intermingling of the two components of the film, and uniform surface morphology. Propagation losses of about 1 dB/cm were measured at 632.8 nm. When pumped with 987 or 514.5 nm continuous-wave laser light, the waveguides show the (4)I(13/2)-->(4)I(15/2) emission band with a bandwidth of 48 nm. The spectral features are found independent both on erbium content and excitation wavelength. The (4)I(13/2) level decay curves presented a single-exponential profile, with a lifetime between 2.9 and 5.0 ms, depending on the erbium concentration. (C) 2002 American Institute of Physics.
Resumo:
Ultrashort-pulse lasers with spectral tuning capability have widespread applications in fields such as spectroscopy, biomedical research and telecommunications. Mode-locked fibre lasers are convenient and powerful sources of ultrashort pulses, and the inclusion of a broadband saturable absorber as a passive optical switch inside the laser cavity may offer tuneability over a range of wavelengths. Semiconductor saturable absorber mirrors are widely used in fibre lasers, but their operating range is typically limited to a few tens of nanometres, and their fabrication can be challenging in the 1.3-1.5 microm wavelength region used for optical communications. Single-walled carbon nanotubes are excellent saturable absorbers because of their subpicosecond recovery time, low saturation intensity, polarization insensitivity, and mechanical and environmental robustness. Here, we engineer a nanotube-polycarbonate film with a wide bandwidth (>300 nm) around 1.55 microm, and then use it to demonstrate a 2.4 ps Er(3+)-doped fibre laser that is tuneable from 1,518 to 1,558 nm. In principle, different diameters and chiralities of nanotubes could be combined to enable compact, mode-locked fibre lasers that are tuneable over a much broader range of wavelengths than other systems.
Resumo:
Er^3+Tm^3+/Yb^3+Raman980nmLD(476nm)(530nm545nm)(656nm)(476nm)Tm^3+1^G43^3H6(530nm545nm)Er^3+2^H11/24^I1524^S3/24^I15/2(6
Resumo:
5OH^-Judd-OfeltOH^-ii=246McCumber1532nmEr^3^4I132^4I15/2Er^3^4I132^4I15/2^4I132OH^-
Resumo:
---(JuddOfelt)Er^3+(McCumber)Er^3+15mEr^3+65nmEr^3+Er^3+--
Resumo:
Er^3/Yb^3. , McCumberEr^31533 nm0.8410^-20 cm^2, ^4I13/28.5 ms. , Er^3/Yb^3. , 80 mW, 16.5%.
Resumo:
Er^3+Er^3+Judd-OfeltEr^3+(2=47910^-20cm^2,4=15210^-20cm^26=06610^-20cm^2)McCumberEr^3+(e=104010^-21cm^2)Er^3+^4I132^4I152(FWHM=655nm)
Resumo:
TgTx3771488552nmMcCumberEr^3+4I132^4I1521532nm09110^-20cm^26328nmAg^+300De28210^-1
Resumo:
Yb^3+-Er^3+P2O5-B2O3-R2O-MO-Al2O3(R=LiNaKM=ZnCaSrBa)B2O3B2O3TgTf
Resumo:
Er^3+Judd-OfeltEr^3+(2=47910^-20cm^24=15210^-20cm^26=06610^-20cm^2)McCumberEr^3+(e=104010^-21cm^2)Er^3+^4I13/2^4I15/2(FWHM=655nm)(^4I13/2rad
Resumo:
A novel Vb(3+)-Er-(3+) codoped phosphate glass for high power flashlamp pumping and high repetition rate laser at 1.54 mu m, designated EAT5-2, is developed. The weight-loss rate of is 1.3 x 10(-5) gcm(-2) h(-1) in boiling water, which is comparable to Kigre's QX-Er glass. Some spectroscopic parameters are analysed by Judd-Ofelt theory and McCumber theory The emission cross section is calculated to be 0.73 x 10(-20) cm(2). The thermo-mechanical properties of EAT5-2 are modified after an ion-exchange chemical strengthening process in a KNO3/NaNO3 molten salt bath. The thresholds for optical damage from the flashlamp pumping are tested on glass rods. A repetition rate of 15 Hz is achieved for chemically strengthened glass. The laser experimental results at. 1.54 mu m from flashlamp pumping are also reported.
