Single‐Mode Lasing Over a Broad Pumping Range in a High‐ Q GaN Hexagonal Microcavity

Single‐mode lasing and high‐quality factors ( Q factors) are critical for microcavity lasers in integrated photonic applications. Here, we propose and demonstrate a GaN‐based hexagonal microcavity laser with a lateral nanoporous distributed Bragg reflector (DBR). Single‐mode lasing is maintained from the lasing threshold up to 13.3 times the threshold pump power, with a side‐mode suppression ratio (SMSR) up to 22.6 dB. The lateral nanoporous DBR provides strong vertical optical confinement, resulting in a low lasing threshold of 0.8 W/cm 2 and a high Q factor of 11389. In addition, simulations of the mode field distribution reveal that a low‐loss triangular resonant mode can effectively suppress high‐order modes to achieve single‐mode behavior. Our findings can offer a straightforward and effective solution to realize single‐mode microcavity lasers with both high SMSRs and Q factors, supporting efficient lasing and improved signal quality for integrated photonic circuits.