Pinel Olivier, Everett Jesse L, Hosseini Mahdi, Campbell Geoff T, Buchler Ben C, Lam Ping Koy
Centre for Quantum Computation and Communication Technology, Department of Quantum Science, Research School of Physics and Engineering, The Australian National University, Canberra ACT 0200, Australia.
Sci Rep. 2015 Dec 10;5:17633. doi: 10.1038/srep17633.
Optical resonance is central to a wide range of optical devices and techniques. In an optical cavity, the round-trip length and mirror reflectivity can be chosen to optimize the circulating optical power, linewidth, and free-spectral range (FSR) for a given application. In this paper we show how an atomic spinwave system, with no physical mirrors, can behave in a manner that is analogous to an optical cavity. We demonstrate this similarity by characterising the build-up and decay of the resonance in the time domain, and measuring the effective optical linewidth and FSR in the frequency domain. Our spinwave is generated in a 20 cm long Rb gas cell, yet it facilitates an effective FSR of 83 kHz, which would require a round-trip path of 3.6 km in a free-space optical cavity. Furthermore, the spinwave coupling is controllable enabling dynamic tuning of the effective cavity parameters.
光学共振是众多光学器件和技术的核心。在光学腔中，可以选择往返长度和镜面反射率，以针对特定应用优化循环光功率、线宽和自由光谱范围（FSR）。在本文中，我们展示了一个没有物理镜面的原子自旋波系统如何能够表现得类似于光学腔。我们通过在时域中表征共振的建立和衰减，并在频域中测量有效光学线宽和FSR来证明这种相似性。我们的自旋波在一个20厘米长的铷气室中产生，但它实现了83千赫兹的有效FSR，这在自由空间光学腔中需要3.6千米的往返路径。此外，自旋波耦合是可控的，能够对有效腔参数进行动态调谐。
