DEPENDENCE OF TI-DIFFUSED ER-LINBO3 LASER EFFICIENCY ON WAVE-GUIDE FABRICATION PARAMETERS AND PUMP WAVELENGTH

The mode size, effective pump area, and coupling efficiency as functio n of initial Ti-stripe width W, diffusion temperature T, and initial T i-stripe thickness H in c-cut Ti-diffused Er : LiNbO3 waveguide laser have been studied theoretically, taking into account optical pumping l ambda(p) = 1.477 mu m and 0.98 mu m, The main features of the mode siz es in terms of these diffusion parameters were collected and, as compa red with the experimental results, a qualitative agreement has been ac hieved, The effective pump areas exhibit both significant initial Ti-s tripe width and diffusion temperature dependence, especially for W > 9 mu m and T > 1050 degrees C, whereas the initial Ti-stripe thickness can hardly give influence when pumping with lambda(p) 0.98-mu m radiat ion, On the other hand, coupling efficiency is approximately unchanged with values 0.76-0.78 for lambda(p) = 1.477 mu m and 0.8-0.85 for lam bda(p) = 0.98 mu m, indicating that there are no optimized values of t hese parameters to increase slope efficiency through coupling efficien cy. Moreover, the 0.98-mu m pumping reveal lower threshold and higher coupling efficiency than 1.477-mu m pumping, Finally, the appropriate waveguide fabrication parameters were proposed for the fabrication of a more efficient laser.