The Investigation Of Er/Yb Co-doped Optical Conmmunication Germinate Glasses Waveguide Material

Low phonon energy glasses doped with trivalent rare-earth ions are attractive due to their potential applications in developing compact solid-state lasers,optical broadband amplifiers and visible display devices.Currently,with operating windows in 1530-1560nm C-band erbium-doped silica fiber has become a mature product,limiting the full utilization of the channels in optical fiber.In order to further broaden the communication windows,attentions have been paid to Pr3+,Tm3+ and Ho3+ doped active optical amplifier.However,the main issue of applying the these three rare earth Pr3+,Tm3+ and Ho3+ is their low luminous efficiency,which can not achieve purposes of all-optical amplification in the second communication window,S-band and U-band.Therefore,the search for new glass matrix material for optical amplifiers with broadband and flattening gain,operating wavelength regions other than extensions to the C-band has become a top priority.Based on this consideration,Er3/Yb3+-doped low phonon energy germanium glasses were designed and synthesized,and the optical and spectral properties of Er3r were studied.K+-Na+ ion-exchange surface of the refractive index in germanium glasses were studied.In addition,the ion-exchange channek waveguide was fabricated in Er3+/Yb3+-doped germanium glasses surface prepared,and its signal gain ability wass characterizaed,laying the foundation for Pr3+,Tm3+ and Ho3+-doped germanium glasses for special-band signal amplifier.The followings are results this work achieved:1.Er3+/Yb3+ co-doped low phonon germanium glasses have been designed and fabricated.Based on optical absorption,Judd-Ofelt parameters Ω2,Ω4 and Ω6 have been derived to be.02×10-20,1.92×10-20 and 0.76×10-20cm2,respectively.Then the radiative transition probabilities,radiative lifetimes and fluorescence branching ratios were calculated.The efficient infrared emission in Er3+/Yb3+ co-doped germanium glasses system has been recorded under the pumping of a 982nm diode laser and Yi3+ is considered to be a preferable sensitizer for catching remarkable pumping energy and transferring considerable energy to Er3+.The maximum absorption and calculated emission cross sections are 5.47×10-21 cm2 and 5.76×10-21 cm2 at 1.53μm,respectively.Low maximum phonon energy and high emission cross sections indicate that Er3+/Yb3+ co-doped low phonnon germanium glasses will be promising infrared laser materials.2.The slab waveguide of alumium germanate glasses was fabricated by K+-Na+ion-exchange.Inverse Wentzel-Kramer-Brillouin(IWKB)method was applied to calculate the effective indices measured with the prism coupler technique,refractive-index profiles were fitted using Gaussian function.The maximum index change △n and the effective diffusion constant De were calculated to be 0.01132 and 1.16×10-4μm2/s,respectively.The effect of the diffusion time on the waveguide properties was further investigated.3.K+-Na+ ion-exchanged channel waveguide amplifiers have been fabricated in Er3+/Yb3+ codoped acid-resistant alumium germanate(NMAG)glasses.The optical gain and the relative gain(the signal enhancement)of a 2.5 cm long waveguide amplifier were measured to be 9.10 dB and 8.16 dB,respectively,and after compensating both the propagation loss and the absorption loss,a maximum internal gain of～2.0 dB at 1.534 μm was obtained,which reveals the successful employment of the thermal ion-exchange technology on the low phonon energy glasses.Based on this work,ion-exchanged Pr3+,Tm3+ and Ho3+ doped NMAG glass waveguides will bring surprises in developing O-,S-and U-band waveguide amplifiers,infrared UV-writing grating waveguide lasers and compact integrated optical devices.