Ultra-low-threshold InGaN/GaN quantum dot micro-ring lasers

作者：Wang Danqing^*; Zhu Tongtong; Oliver Rachel A; Hu Evelyn L

来源：Optics Letters, 2018, 43(4): 799-802.

DOI：10.1364/OL.43.000799

In this work, we demonstrate ultra-low-threshold, optically pumped, room-temperature lasing in GaN microdisk and micro-ring cavities containing InGaN quantum dots and fragmented quantum wells, with the lowest measured threshold at a record low of 6.2 mu J/cm(2). When pump volume decreases, we observe a systematic decrease in the lasing threshold of micro-rings. The photon loss rate,., increases with increasing inner ring diameter, leading to a systematic decrease in the post-threshold slope efficiency, while the quality factor of the lasing mode remains largely unchanged. A careful analysis using finite-difference time-domain simulations attributes the increased gamma to the loss of photons from lower-quality higher-order modes during amplified spontaneous emission. Published by The Optical Society under the terms of the Creative Commons Attribution 4.0 License.

• 出版日期2018-2-15