Er^(3+)-Yb^(3+) Co-Doped Fiber Ring and Line Laser

Er3+-Yb3+ co-doped fiber of 2 m long is used as the laser gain medium. Two fiber lasers with different structures have been set up, one is the line cavity fiber laser with the dielectric mirror being replaced by an all-fiber reflecting mirror,the other is the ring cavity all-fiber laser. Both set-ups have achieved lasing operation at the wavelength of 1.53 μm. Pumped by the 1 064 nm light from all-solid-state Nd ∶YAG laser, the two fiber lasers at 1 530 nm are operational. Their output powers are 7.8 mW and 2 mW with 130 mW and 160 mW pump powers.

All-fiber Based Er^(3+)∶Yb^(3+) Co-doped Fiber Laser

An all-fiber based Er~ 3+ ∶Yb~ 3+ co-doped double clad fiber laser operating at 1550nm is demonstrated. By using 9m long Er~ 3+ ∶Yb~ 3+ co-doped fiber(EYDF) as the gain medium, and using a pair of fiber Bragg gratings as wavelength filters, the line-width of the output laser is as narrow as 0.2nm and the output power is more than 6mW. The fluorescent effect of the laser before its emission is also studied. And it is found that the Er~ 3+ ∶Yb~ 3+ co-doped double-clad fiber laser also exhibits a high gain for Yb~ 3+ transition near 1080nm.

Optical temperature sensor based on up-conversion fluorescence emission in Yb^(3+):Er^(3+) co-doped ceramics glass

yb^3＋：Er^3＋ co-doped oxy-fluoride ceramics glass has been prepared. The mechanism of up-conversion emissions about Er^3＋ was discussed, and the temperature properties of green up-conversion fluorescence between 303 and 823 K were investigated. The results show that the sensitivity of this sample reaches its maximum value, about 0.0047 K^-1, when the temperature is 383 K, indicating that this kind of sample can be used as high temperature and high sensitivity optical temperature sensor.

Spectral and Lasing Properties of Er^(3+0/Yb^(3+) Co-Doped Phosphate Glasses Pumped by LD

Er^3 ＋/Yb^3 ＋ phosphate glasses were fabricated. According to McCumber theory, the stimulated emission cross-section of Er^3＋ ions at 1533 nm was calculated on the basis of absorption spectrum, and 0.84 × 10^-20 cm^2 is derived, the fluorescence lifetime of ^4I13/2 level is 8.5 ms. An Er^3＋/Yb^3＋ co-doped phosphate glass CW laser pumped by LD was demonstrated at room temperature. The maximum output power is 80 mW and slope efficiency is 16.5%.

Up-conversion luminescence properties and energy transfer of Er^(3+)/Yb^(3+)co-doped oxyfluoride glass ceramic containing CaF_2 nano-crystals

The Er^3＋/yb^3＋ co-doped transparent oxyfluoride glass-ceramics containing CaF2 nano-crystals were successfully prepared. After heat treatments, transmission electron microscopy （TEM） images showed that CaF2 nano-crystals of 20-30 nm in diameter precipitated uniformly in the glass matrix. luminescence of Er^3＋ at 540 nm and 658 nm was observed in Comparing with the host glass, high efficiency upconversion the glass ceramics under the excitation of 980 nm. Moreover, the size of the precipitated nano-crystals can be controlled by heat-treatment temperature and time. With the increase of the nano-crystal size, the intensity of the red emission increased more rapidly than that of the green emission. The energy transfer process of Er^3＋ and Yb^3＋ was convinced and the possible mechanism of Er^3＋ up-conversion was discussed.

Up-conversion photoluminescence characteristics of Yb^(3+):Er^(3+):Tm^(3+) co-doped borosilicate glasses

Yb^3＋：Er^3＋：Tm^3＋co-doped borosilicate glasses are prepared. Their strong up-conversion photoluminescence spectra in a range from ultra-violet to near-infrared, which are excited by a 978-nm laser diode, are measured, and the mechanisms of energy transfer among Yb^3＋ Er^3＋ and Tm^3＋ ions are discussed. The results show that there is an unexpected wavelength at 900-nm emission from Yb^3＋ Stark splitting levels to pump Tm^3＋ ions and there exists an optimum pump power. The concentration of the Tm^3＋ dopant gives rise to a prominent effect on the intensity of visible and near-infrared emissions for the yb^3＋：Er^3＋：Tm^3＋ co-doped borosilicate glasses.

Influence of Input Pulse Durations on Properties of Er^(3+)/Yb^(3+) Co-doped DCFA

Based on propagation-rate equations, the influence of different input pulse durations on the properties of Er^3＋/Yb^3＋ co-doped double-clad fiber amplifier at dynamic equilibrium was analyzed. The change characteristic of output power sag with pulse duration and repetition rate was shown. Whether single or multichannel input pulses are amplified, the shorter the input pulse duration is, the smaller the power sags of output pulse will be. At low repetition rate, upper gain values（Gupper） of gain swing are almost the same for different input pulse durations, which tend to the small signal gain, but lower gain value（Glower） of short input pulse is larger than that of long input pulse. At highrepetition rate, lower gain value（Glower） approaches to upper gain value（Glower）.

Near-infrared carbon-implanted Er^3＋/yb^3＋ co-doped phosphate glass waveguides

The Er3＋/yb3＋ co-doped phosphate （EYDP） glass waveguides operated at 1539 nm have been manufactured by using the implantation technique of carbon ions under the condition of 6.0 MeV energy and 5.0 × 10^13 ions/cm2 fluence in this work. The ion implantation process was computed by means of the stopping and range of ions in matter. The dark-mode spectrum at 1539 nm of the waveguide was recorded by the method of the prism coupling measurement. The microscopic image of the fabricated structure was photographed by an optical microscope. It is the first step for the application of the waveguides on the base of EYDP glasses in optical- integrated photonic devices at near-infrared band.

不同泵浦方式下Er^(3+)/Yb^(3+)共掺光纤放大器的自发辐射谱

用改进的MCVD法和湿法掺杂技术设计制作了2种不同Er3+、Yb3+浓度比的Er3+/Yb3+共掺光纤(EYDF),利用980 nm和1 480 nm泵浦LD对Er3+/Yb3+共掺光纤放大器(EYDFA)的放大自发辐射(ASE)谱进行了研究。利用980 nm LD泵浦时,这2种光纤在C波段的ASE强度都很弱,吸收系数小的EYDF在C波段的荧光强度比吸收系数大的光纤大2个量级。用1 480 nm LD对吸收系数大的EYDF进行泵浦,优化光纤长度,此时C波段荧光强度比用980 nm泵浦时大5个量级。这是由于对于EYDF在976 nm附近Yb3+有很强的非饱和吸收,导致能量传输效率差,因此980 nm LD不适合做高浓度EYDFA的泵浦源。而1 480 nm泵浦时,Yb3+不再作为敏化剂而只起到克服成对Er3+间的浓度淬灭问题,同时起到提高Er3+在石英基光纤中的溶解度的作用。

Upconversion photoluminescence properties of SrY_2O_4:Er^(3+),Yb^(3+) under 1550 and 980 nm excitation

Er^3＋/Yb^3＋ co-doped SrY2O4 phosphors with high color purity and brightness were successfully synthesized via a solid-state reaction method.Luminescence spectrum studies showed that the main red peaks and the minor green peaks of upconversion emissions were located at approximately 634–681 nm and 543–570 nm,respectively,corresponding to the transitions of ~4F（9/2）→~4I（15/2） and ~4S（3/2）→~4I（15/2） of Er^3＋ ions.Under the excitation of 980 and 1550 nm lasers,the spectra of all of the samples exhibited similar peak positions but different intensities.When excited by the 980 nm laser,the intensity ratio of red to green emission increased with increasing Yb^3＋ doping concentration and decreased with increasing excitation power.In the case of 1550 nm excitation,the intensity ratio of red to green emission increased with increasing Yb^3＋ doping concentration and excitation power,thereby,improving the color purity of the red emission.The intensity of red emission was considerably stronger under 1550 nm excitation than that under 980 nm excitation.Therefore,the color of the proposed phosphors could be efficiently tuned by tailoring both the Yb^3＋ doping concentration and excitation power.

大功率L波段全光纤超荧光光源

利用高功率泵浦的双包层Er3+/YB3+共掺光纤(EYDF)放大器,对L波段小信号源进行放大,在1.668 W泵浦光下,获得了波长范围在1 568～1 597 nm、功率达216 mW的超荧光输出.对单程和双程2种放大结构进行了比较详细的对比研究.结果表明:2种结构均可以得到高功率L波段超荧光输出,但双程结构具有比单程结构更高的转换效率和更大的增益;通过增加小信号源的功率,可以有效地抑止短波长激光的产生,并在一定程度上平坦L波段的光谱.