Ultra-low threshold gallium nitride photonic crystal nanobeam laser

作者：Niu Nan^*; Woolf Alexander; Wang Danqing; Zhu Tongtong; Quan Qimin; Oliver Rachel A; Hu Evelyn L

来源：Applied Physics Letters, 2015, 106(23): 231104.

DOI：10.1063/1.4922211

We report exceptionally low thresholds (9.1 mu J/cm(2)) for room temperature lasing at similar to 450 nm in optically pumped Gallium Nitride (GaN) nanobeam cavity structures. The nanobeam cavity geometry provides high theoretical Q (>100 000) with small modal volume, leading to a high spontaneous emission factor, beta = 0.94. The active layer materials are Indium Gallium Nitride (InGaN) fragmented quantum wells (fQWs), a critical factor in achieving the low thresholds, which are an order-of-magnitude lower than obtainable with continuous QW active layers. We suggest that the extra confinement of photo-generated carriers for fQWs (compared to QWs) is responsible for the excellent performance.

• 出版日期2015-6-8