Optical Path Design and Gain Anticipation in Tm3+ Doped Glass Channel Waveguide for U-Band Amplification

To achieve effective U-band integrated amplification in a cm2 glass substrate, bent waveguide structure (U-bend) based on Tm3+ doped germanate glass substrate has been designed. Using simulated-bend method, the optimal radius for the curved structure is offered to be 2.30 cm with a bending loss coefficient of 0.054 dB/cm. For the U-bend waveguide, the evident signal gain is anticipated in the wavelength range of U-band, and the ideal internal gain is derived to be 5.77 dB at 1675 nm wavelength, which is two times higher than 2.52 dB in the straight one. Simulation results indicate that reasonable optical path design can enhance the optical gain in Tm3+ doped germanate glass channel waveguides considerably, which provides a feasible designing idea in realizing practical applications for U-band amplification devices.