de Vries Oliver, Plötner Marco, Christaller Florian, Zhang Hao, Belz Annika, Heinrich Benjamin, Kübler Harald, Löw Robert, Pfau Tilman, Walbaum Till, Schreiber Thomas, Tünnermann Andreas
Opt Express. 2020 Jun 8;28(12):17362-17373. doi: 10.1364/OE.394519.
The development of highly customized technical devices is a decisive feature of technically complex setups, as frequently observed in quantum experiments. This paper describes the development and realization of an Yb-doped all-fiber amplifier system designed for such a special application, more specifically, an on-demand single-photon source based on four-wave mixing with rubidium Rydberg atoms. The laser is capable of generating bandwidth-limited configurable nanosecond pulses up to peak powers of >100 W and with pulse repetition frequencies (PRF) between 50 Hz and 1 MHz at selectable wavelengths (1008-1024 nm). Especially the amplification of the 1010 nm reference seed at the lower edge of the amplification range for Yb-based fibers is challenging and tends to produce amplified spontaneous emission (ASE) at higher wavelengths. To achieve high ASE suppression, particularly at low pulse repetition frequencies, two acousto-optical modulators (AOM) are utilized both for pulse picking and for temporal filtering. The synchronization between pulse repetition frequency and AOM driver signal allows pulse amplitude fluctuations to be kept below 1%, while ASE is suppressed by at least 85 dB (PRF = 1 MHz) and 65 dB (PRF = 1 kHz).
高度定制化技术设备的开发是技术复杂装置的一个决定性特征，这在量子实验中经常可以观察到。本文描述了一种为这种特殊应用而设计的掺镱全光纤放大器系统的开发与实现，更具体地说，是一种基于与铷里德堡原子的四波混频的按需单光子源。该激光器能够产生带宽受限的可配置纳秒脉冲，峰值功率高达100W以上，脉冲重复频率（PRF）在50Hz至1MHz之间，波长可在1008 - 1024nm之间选择。特别是在基于镱的光纤的放大范围下限处对1010nm参考种子光的放大具有挑战性，并且往往会在更高波长处产生放大自发辐射（ASE）。为了实现高ASE抑制，特别是在低脉冲重复频率下，使用了两个声光调制器（AOM）进行脉冲拾取和时间滤波。脉冲重复频率与AOM驱动信号之间的同步使得脉冲幅度波动保持在1%以下，而ASE被抑制至少85dB（PRF = 1MHz）和65dB（PRF = 1kHz）。
