Liu Xiao-Fei, Wang Tie-Jun, Wang Chuan
Opt Lett. 2018 Jan 15;43(2):326-329. doi: 10.1364/OL.43.000326.
Erbium-doped whispering-gallery-mode (WGM) microcavities have great potential in many important applications, such as the precision detection and the micro/nano laser. However, they are sensitive to the fluctuations from the pump laser and the environment. Here we demonstrate the precise controlling of transmission spectra and optical gains using optothermal scanning methods in erbium-doped WGM microcavities. The transmission spectrum of the probe signal exhibits the transition between asymmetric Fano-like resonance and the Lorentz peak (or dip) through tuning the input frequency and the scanning speed of the pump laser. In particular, the analytical calculations can fit well with our experimental results through adiabatically eliminating the anticlockwise optical mode. This Letter shows that the optothermal control of gains is more robust to external noises, which paves a crucial step toward the application in the ultra-sensitive detection.
掺铒回音壁模式（WGM）微腔在许多重要应用中具有巨大潜力，如精密检测和微纳激光。然而，它们对泵浦激光和环境的波动很敏感。在此，我们展示了在掺铒WGM微腔中使用光热扫描方法对透射光谱和光学增益进行精确控制。通过调谐泵浦激光的输入频率和扫描速度，探测信号的透射光谱呈现出非对称类法诺共振与洛伦兹峰（或谷）之间的转变。特别是，通过绝热消除逆时针光学模式，解析计算结果与我们的实验结果吻合良好。本信函表明，增益的光热控制对外部噪声更具鲁棒性，这为超灵敏检测应用迈出了关键一步。
