The Compact Designing of Long Optical Path Simulation and Gain Evaluation in Rear-earth Doped Germinate Glass Waveguide Amplifier
|School||Dalian University of Technology|
|Keywords||Planar waveguide BeamPROP simulation Optical path design Opticalgain|
In recent years, with the rapid development of internet and digital communicationservices, all-optical communication networks gradually spread to personal and home users.Small, highly integrated and large capacity optical waveguide devices become a researchhotspot. The rear earth doped glass waveguide amplifier has attracted increasing attention asan important communication networks in all-optical devices. The C-band （15301565nm）has received creative progress, the S-band （15301565） gradually becomes a potentialcommunication resource. Nowadays, the C-/S-band fiber amplifiers have been successfullyfabricated. The waveguide device with small size, high gain coefficient, and overwhelmlyintegrated density appears to be a better choice. However, the optical amplification path of thewaveguide is much shorter than fiber amplifier. It is hard for waveguides to obtain the enoughgain in an integrated panel to meet the requirements of signal amplification, which severelyrestrict the practical application of the waveguide amplifiers.To obtain efficient gains for the practical application of the waveguide amplifiers,enhancing the doping concentration of rear-earth ions and amplification path in the substratesare two feasible routes. However, cross-relaxation of rear-earth lowers the efficiency ofamplification obviously when the doping concentration is excessive. Thus, by comparisonwith increasing doping concentration of rear-earth, lengthening the amplification path is moreappreciated in realizing the high gain of the interesting band.Considering the previous situation, base on the Er3+/Yb3+codoped and Tm3+dopedNMAG（23Na2O-3MgO-22Al2O3-52GeO） substrate in a （86） cm2area, we design theS-bend, U-bend, and F-bend waveguides and use the BPM to access the loss of thewaveguide. By calculating the bend and transition losses, the gains of the three curvedwaveguides are anticipated. Because the intrinsic emission curve of Er3+/Yb3+codopedwaveguide is not flat, so the gain improve is not stable. For Tm3+doped waveguide, the losscoefficient is0.04dB/cm. For the F-bend waveguide, the internal gain at1482nm is derivedto be13.01dB, which is higher than the values of8.21and4.22dB in the U-and S-bend waveguides, respectively, and nearly three times higher than that of the straight one.Simulation results indicate that reasonable optical path design can enhance the optical gain forrear earth doped germanate glass channel waveguides considerably, which provides a feasibledesigning idea in realizing practical applications for wide band amplifying devices.