Single mode compound microsphere laser

Single mode laser is demonstrated based on compound microspheres. The two coupled microspheres, corresponding to the diameters of 32.7 μm and 49.2 μm, are both made from Er3+/Yb3+ co-doped phosphate glass. Based on the Vernier effect, single mode laser emission has been realized at 1544.43 nm with the side-mode suppression ratio of 45.1 dB and the threshold of only 163 μW. This compound microspheres scheme can effectively select one laser emission mode among various modes, which can potentially used in micro-size laser source, high precision sensor and other frontier fields.