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Research On Luminescence And Application Of New Type Re-doped Glass As Laser Material

Posted on:2003-01-05Degree:MasterType:Thesis
Country:ChinaCandidate:C H NiuFull Text:PDF
GTID:2168360062490819Subject:Optics
Abstract/Summary:PDF Full Text Request
In this paper, the author firstly introduces the relative preparation technology of rare earth doped glassy laser materials and some theories about luminescence of rare earth ions, Then shows his work results done for master degree. Research on preparation and luminescence of rare earth doped tellurite and phosphate glassy laser materials is author's mainly researched topics. In addition, the author has also studied for the application about the two kinds of materials. The summary about this paper is as follows: By adjusting the composition of the glass, the author prepared two kinds of glassy laser material: tellurite glass(shorten form: TBZRE) and phosphate glass(shorten form:NPRE-1). The TBZRE glass has great forming ability, which can form glassy body under relative slow cooling ratio. Moreover, the technique of glass's annealing is easy. The NPRE-1 glass has strong viscosity. One can draw a thread more than one meter by handcraft. The NPRE-1 glass thread has also strong tenacity, not easy to be fractured. So the NPRE-1 can specially be applied to fabricate light fiber. Compared to routine Q89 phosphate laser galss(Tg=440℃), the transformation temperature of the NPRE-1 glass is higher(Tg=530℃),which is fit to ion-exchang craft fabricating light waveguide. The upconversion luminescence in TBZRE glass at room temperature was studied. Under 970nm-wavelength laser diode pumped, high efficient upconversion fluorescence near 480nm has been attained. From the comparison among luminescence intensity in samples with several different concentration, we can observe concentration quenching feature in these glasses. Then we analyzed the reason on concentration-quenching which could be attributed to cross-relaxation mechanism. We also performed a nonlinear curve fitting to the intensity relation curve between pumped light and upconversion emission light, and knew that the upconversion luminescence belonged to three-photon absorption. Furthermore, the upconvesion luminescence about 650nm and 808nm is also reached. They respectively belonged to three-photon and two-photon absorption. The author has calculated the spontaneous radiate probabilities, the linear oscillator strengths, branching ratio of Tm3+ iones by Judd-Oflet theory. According to the J-O calculated data, the transition 1G4—3H6 was stronger than the transition 1G4—3H4.It was agreement with the emission spectra. Moreover, the cross section of 481nm and 650nm upconversion emission have also been calculated. The author has measured the absorption spectrum of the NPRE-1 glass and observed a strong absorption near 970 nm. The emission spectrum under 970 nm LD excitation have also been acquired. In this spectrum, Only a strong emission near 1540 nm wavelength can be observed. By formula about effective bandwidth, he get the bandwidth near 1540 nm wavelength ,which is 64.54nm.The bandwidth is more bigger than the gain bandwidth of Er-doped silica fiber and fluoride fiber amplifier(20nm-30nm).it is useful to improve transmitted capacity of information in fiber.By calculated Judd-Ofelt parameters of the NPRE-1 glass and luminescence dynamics equation, the author has get the changing curve about light intensity near 1540nm with the increase of Er doped concentration. It was observed that the light intensity is the strongest when Er doped concentration is 20mol% and the concentration-quenching phenomenon takes place after the concentration is bigger than 20mol%.Research on preparation of light waveguide with NPRE-1 glass has been done. By controlling the time of ion-exchang craft, the author has gotten some light waveguide with different thickness. Then, the author observed light mode about these samples by means of prism-coupling method. It can be proved that this new kind of NPRE-1 glass entirely possessed the qualification for preparing light waveguide. This achievement has created good condition for making light waveguide laser.
Keywords/Search Tags:J-O theory, upconversion luminescence, energy transfer, Concentration quenching, emission cross section.
PDF Full Text Request
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