Design of Vernier ring for external cavity laser with high side mode suppression ratio and wide tuning range

Chip-scale external-cavity lasers with a wide tuning range and a narrow linewidth are widely used in optical communication, optical sensing, and optical detection systems. The reflector cavities of such lasers typically consist of Vernier ring structure, but conventional design with wide tuning range is difficult to achieve a high side mode suppression ratio. Here, we use a novel radius optimization method to achieve the product of side mode suppression ratio and tuning range 2141.2 and firstly analyze how the method works. And the external cavity laser simulation obtains side mode suppression ratio about 80 dB, tuning range 106 nm and power above 10 dBm. This result is ahead of the result obtained by conventional design method. It promotes the development of external-cavity lasers by realizing reflector cavities with high side mode suppression ratio and wide tuning range.