Design and Analysis of Wavelength Tunable HighSlope Efficiency and Output Power Er-Yb:Co-dopedWaveguide Laser

In this paper, we demonstrate a wavelength tunable high slope efficiency and on-chip output power single-longitudnal modeErbium-Ytterbium:co-doped waveguide laser (EYCDWL) operating in C-band. The proposed laser is implemented using 1 cmlong Erbium-Ytterbium (Er-Yb):co-doped waveguide (EYCDW) built on a Lithium Niobate on insulator (LNOI) platform anda single 980 nm backward pump. Wavelength tuning of 35 nm in the range of 1530-1565 nm is achieved with side-modesuppression ratio (SMSR) over 59 dB for coupling ratios of 40%, 50% and 60%. Highest slope efficiency (SE) and on-chipoutput power of 67.2% and 318 mW, respectively are achieved at lasing wavelength of 1545 nm for coupling ratio of 50%.Similarly, minimum linewidth (LW) of 125 MHz is observed for lasing wavelength of 1550 nm considering 60% of the couplingratio. Power variation around 0.13 mW has been observed for lasing wavelength of 1545 nm considering 50% of the couplingratio based on twelve iterations each repeating after five-minute interval. Finally, the impact of energy transfer upconversion(UC) on output power of EYCDWL is also analyzed. A power penalty of around 100 mW is observed in on-chip lasing power.This tunable laser can be a potential candidate to integrate with other photonic components which include wavelength lockers,modulators, and photodetectors, realizing complete photonic integrated chips (PICs) for various applications, such as shortreach free-space optical communication, sensing, and next-generation computing applications.