A Stable 1550nm WGM Laser Generated by Yb3+/Er3+ Co-doped Silica Microspheres under μm ASE Source Pumping
Abstract The amplified spontaneous emission (ASE) light source at 1 μm was used to excite Yb3+/Er3+ co-doped silica (YEDS) microspheres by evanescent-wave coupling through a taper optical fiber (TOF) to generate a stable 1550 nm laser. Inevitably, the experimental process was accompanied by a frequency up-conversion luminescence whose fluorescence spectrum was collected and analyzed. Pumped by the ASE light source with different power, the system of YEDS microsphere and TOF also generated single-mode laser and multi-longitudinal mode laser. Their peak wavelength, output power of the peak laser, full width at half maximum (FWHM), and side mode suppression ratio (SMSR) were respectively measured. Moreover, the characteristics of a 1550 nm whispering gallery mode (WGM) laser excited by a 1 μm ASE pumping and a tunable laser (TLS) pumping were compared under different variable conditions. It was demonstrated that the ASE pump source has polarization in all directions to excite WGMs in the microsphere cavity, which was different from and superior to the TLS. Therefore, the laser generated by the ASE pump source as an excitation source was not affected by vibration and temperature change. The results show that the 1550 nm laser pumped by ASE can stably output the microsphere WGM mode laser under the interference of vibration and temperature change, which is more suitable for the actual application environment.
