Tm^(3+)-doped tellurite glass with Yb^(3+) energy sensitized for broadband amplifier at 1400–1700 nm bands

A kind of novel experiment was disclosed as it possessed two bands of fluorescence emission at 1.4 and 1.6 μm, which were perfectly complimentary to the current C band of optic communication. The fluorescence was based on energy transfer and up-conversion processes between Tm^3＋ and Yb^3＋ under direct pumping of 975 nm LD. The spectra and lifetimes of Tm^3＋ fluorescence in the tellurite glass were described. The corresponding fluorescence characteristics and energy migration process were analyzed by the method of lifetime and intensity comparison. The mechanism of the up-conversion based IR fluorescence was presented upon analyzing the multi-photon pumping process. The potential advantages of Tm^3＋/Yb^3＋ co-doped tellurite glass as amplifier material were concluded.

Effects of Ce^(3+) doping on the structure and magnetic properties of Mn-Zn ferrite fibers

Ce3+-doped Mn-Zn ferrite fibers were successfully prepared by the organic gel-thermal decomposition method from metal salts and citric acid. The composition,structure,and magnetic properties of these ferrite fibers were characterized by X-ray diffraction (XRD),scanning electron microscopy (SEM),and vibrating sample magnetometer (VSM). The results show that Mn0.2Zn0.8Fe2-xCexO4 (x = 0-0.04) fibers are featured with an average grain size of 11.6-12.7 nm,with diameters ranging between 1.0 to 3.5 μm and a high ...

Gain properties of germanate glasses singly doped with Tm^(3+) and Ho^(3+) ions

Two kinds of germanate glasses singly doped with the ion concentration of 2.0mol.%Tm3＋ and 2.0mol.%Ho3＋, respectively, were prepared.According to McCumber theory, the absorption and stimulated emission cross-sections corresponding to the 3H6←→3F4 transitions of Tm3＋（at 1.8 μm） and the 5I8←→5I7 transitions of Ho3＋（at 2.0 μm） were obtained, and respective gain cross-section spectra were also computed as a function of population inversion according to absorption and emission cross-sections and the ion concentrations.For Tm3＋-doped germanate glasses, the maximum of the absorption, emission, and gain cross-sections reached a value higher than those reported for fluorozirconate, fluoride, and oxyfluoride glasses.For Ho3＋-doped germanate glasses, the maximum of absorption, emission, and gain cross-sections reached a value higher than that reported for fluorozircoaluminate glasses.Hence, these Tm3＋-doped and Ho3＋-doped germanate glasses exhibited an advantage for application in mid-infrared lasers at about 1.8 and 2.0 μm wavelength.

Mode-locked fiber lasers at 1064 and 910 nm wavelengths using Nd^(3+)-doped silica fiber

Mode-locked lasing operations at 1064 and 910 nm wavelengths are demonstrated,respectively,in two all-fiber laser oscillators using our homemade Nd^(3+)-doped silica fiber(NDF)as the gain medium.The Al3+/Nd^(3+)co-doped silica core glass was fabricated by the modified sol-gel method with 18,300×10^(-6) Nd^(3+)doping concentration.The NDF drawn by the rodin-tube method has a core of 4μm in diameter and a numerical aperture(NA)of 0.14.At 1064 nm,we measure an average laser output power of 18mWwith a pulse duration of 5.75 ps,a pulse energy of 1.14 nJ,and a slope efficiency of 7.2%.Using the same NDF gain fiber of a different length,a maximum average laser output power is 3.1 mW at 910 nm with a pulse duration of 877 ns,a pulse energy of 2.7 nJ,and a slope efficiency of 1.44%.

3.6 W compact all-fiber Pr3+-doped green laser at 521 nm

Green semiconductor lasers are still undeveloped,so high-power green lasers have heavily relied on nonlinear frequency conversion of near-infrared lasers,precluding compact and low-cost green laser systems.Here,we report the first Watt-level all-fiber CW Pr3t-doped laser operating directly in the green spectral region,addressing the aforementioned difficulties.The compact all-fiber laser consists of a double-clad Pr3t-doped fluoride fiber,two homemade fiber dichroic mirrors at visible wavelengths,and a 443-nm fiber-pigtailed pump source.Benefitting from>10 MW∕cm2 high damage intensity of our designed fiber dielectric mirror,the green laser can stably deliver 3.62-W of continuous-wave power at∼521 nm with a slope efficiency of 20.9%.To the best of our knowledge,this is the largest output power directly from green fiber lasers,which is one order higher than previously reported.Moreover,these green all-fiber laser designs are optimized by using experiments and numerical simulations.Numerical results are in excellent agreement with our experimental results and show that the optimal gain fiber length,output mirror reflectivity,and doping level should be considered to obtain higher power and efficiency.This work may pave a path toward compact high-power green all-fiber lasers for applications in biomedicine,laser display,underwater detection,and spectroscopy.

Multiphoton process and optical amplification in Er^(3+)-Yb^(3+)-doped fiber pumped by Ti:Al_2O_3 tunable laser at 980-nm band

The .Er3+-Yb3+-doped fiber has a broadened absorption spectrum, which means the pumping sources can work efficiently from 810 to 1100nm. Among them 980nm is the maximum.absorption （10 dB/km） wavelength. By energy transferring and multiphoton process, the visible and ultraviolet radiation occurs when the Er3+-Yb3+-doped fiber is pumped by the laser at 980-nm band. Further researches on the mechanism of the fluorescence of Er3+-Yb3+-doped silica fiber pumped by Ti: A12O3 tunable laser at 980-nm band are helpful

Generation of 100 nJ pulse,1 W average power at 2μm from an intermode beating mode-locked all-fiber laser

We report on the investigation of intermode beating mode-locked(IBML)pulse generation in a simple all-fiber Tm^3+-doped double clad fiber laser(TDFL).This IBML TDFL is implemented by matching longitudinal-mode frequency between 793 nm laser and TDFL without extra mode locker.The central wavelength of 1983 nm,the fundamental pulse frequency of 9.6 MHz and the signal-to-noise ratio(SNR)of>50 dB are achieved in this IBML TDFL.With laser cavity optimization,the IBML TDFL can finally generate an average output power of 1.03 W with corresponding pulse energy of 107 nJ.These results can provide an easily accessible way to develop compact large-energy,highpower TDFLs.