标题： 在GaAs量子阱微腔中观察由玻色子库驱动的激光到费米子库驱动的激光的转变 显示英文标题

标题： Observation of the transition from lasing driven by a bosonic to a fermionic reservoir in a GaAs quantum well microcavity

摘要： 我们表明，通过在非共振脉冲光泵浦下监测基于GaAs的量子阱微腔中的自由载流子库，可以区分由费米子库（光子激光）支持的激光与由玻色子库（极化子激光）支持的激光。 通过测量在微腔的量子阱上直接沉积的侧向接触之间的光电流来探测载流子密度，这些量子阱通过湿化学刻蚀部分暴露。 我们在光致发光信号的输入输出特性中识别出两个清晰的阈值，分别可以归因于极化子激光和光子激光。 探测的光电流的功率依赖性在光子激光的阈值功率处显示出明显的拐点，这是由于受激发射进入腔模式时自由载流子的辐射复合增加所致。 另一方面，在极化子激光阈值处，发光的非线性增加是由于激子极化子受激散射到不直接对光电流做出贡献的基态。 显示英文摘要

摘要： We show that, by monitoring the free carrier reservoir in a GaAs-based quantum well microcavity under nonresonant pulsed optical pumping, lasing supported by a fermionic reservoir (photon lasing) can be distinguished from lasing supported by a reservoir of bosons (polariton lasing). Carrier densities are probed by measuring the photocurrent between lateral contacts deposited directly on the quantum wells of a microcavity that are partially exposed by wet chemical etching. We identify two clear thresholds in the input-output characteristic of the photoluminescence signal which can be attributed to polariton and photon lasing, respectively. The power dependence of the probed photocurrent shows a distinct kink at the threshold power for photon lasing due to an increased radiative recombination of free carriers as stimulated emission into the cavity mode sets in. At the polariton lasing threshold, on the other hand, the nonlinear increase of the luminescence is caused by stimulated scattering of exciton polaritons to the ground state which do not contribute directly to the photocurrent.