Yüce Emre, Ctistis Georgios, Claudon Julien, Gérard Jean-Michel, Vos Willem L
Opt Express. 2016 Jan 11;24(1):239-53. doi: 10.1364/OE.24.000239.
We have switched GaAs/AlAs and AlGaAs/AlAs planar microcavities that operate in the "Original" (O) telecom band by exploiting the instantaneous electronic Kerr effect. We observe that the resonance frequency reversibly shifts within one picosecond when the nanostructure is pumped with low-energy photons. We investigate experimentally and theoretically the role of several parameters: the material backbone and its electronic bandgap, the quality factor, and the duration of the switch pulse. The magnitude of the frequency shift is reduced when the backbone of the central λ-layer has a greater electronic bandgap compared to the cavity resonance frequency and the frequency of the pump. This observation is caused by the fact that pumping with photon energies near the bandgap resonantly enhances the switched magnitude. We thus find that cavities operating in the telecom O-band are more amenable to ultrafast Kerr switching than those operating at lower frequencies, such as the C-band. Our results indicate that the large bandgap of AlGaAs/AlAs cavity allows to tune both the pump and the probe to the telecom range to perform Kerr switching without detrimental two-photon absorption. We observe that the magnitude of the resonance frequency shift decreases with increasing quality factor of the cavity. Our model shows that the magnitude of the resonance frequency shift depends on the pump pulse duration and is maximized when the duration matches the cavity storage time to within a factor two. In our experiments, we obtain a maximum shift of the cavity resonance relative to the cavity linewidth of 20%. We project that the shift of the cavity resonance can be increased twofold with a pump pulse duration that better matches the cavity storage time. We provide the essential parameter settings for different materials so that the frequency shift of the cavity resonance can be maximized using the electronic Kerr effect.
我们通过利用瞬态电子克尔效应，切换了在“原始”（O）电信频段工作的砷化镓/砷化铝和铝镓砷/砷化铝平面微腔。我们观察到，当用低能量光子泵浦纳米结构时，共振频率在一皮秒内可逆地移动。我们从实验和理论上研究了几个参数的作用：材料骨架及其电子带隙、品质因数和开关脉冲的持续时间。当中心λ层的骨架相对于腔共振频率和泵浦频率具有更大的电子带隙时，频移的幅度会减小。这一观察结果是由于用接近带隙的光子能量进行泵浦会共振增强开关幅度。因此，我们发现，在电信O频段工作的腔比在较低频率（如C频段）工作的腔更适合超快克尔开关。我们的结果表明，铝镓砷/砷化铝腔的大带隙允许将泵浦和探测都调谐到电信范围，以进行克尔开关而不会产生有害的双光子吸收。我们观察到，共振频率移动的幅度随着腔品质因数的增加而减小。我们的模型表明，共振频率移动的幅度取决于泵浦脉冲持续时间，并且当持续时间与腔存储时间匹配在两倍因子范围内时达到最大值。在我们的实验中，我们获得了相对于腔线宽20%的腔共振最大移动。我们预计，使用与腔存储时间更匹配的泵浦脉冲持续时间，腔共振的移动可以增加两倍。我们提供了不同材料的基本参数设置，以便利用电子克尔效应使腔共振的频移最大化。
