Acoustic waves can serve as memory for optical information; however, propagating acoustic phonons in the gigahertz (GHz) regime decay on the nanosecond time scale. Usually this is dominated by intrinsic acoustic loss due to inelastic scattering of the acoustic waves and thermal phonons. Here we show a way to counteract the intrinsic acoustic decay of the phonons in a waveguide by resonantly reinforcing the acoustic wave via synchronized optical pulses. We experimentally demonstrate coherent on-chip storage in amplitude and phase up to 40 ns, 4 times the intrinsic acoustic lifetime in the waveguide. Through theoretical considerations, we anticipate that this concept allows for storage times up to microseconds within realistic experimental limitations while maintaining a GHz bandwidth of the optical signal.

中文翻译：

---

相干刷新高超音速声子以存储光

声波可以充当光学信息的存储器；但是，千兆赫兹（GHz）范围内传播的声子在纳秒级时衰减。通常，这主要是由于声波和热声子的非弹性散射导致的固有声损耗。在这里，我们展示了一种通过同步光脉冲通过共振增强声波来抵消波导中声子固有声衰变的方法。我们通过实验证明了片上相干存储的幅度和相位高达40 ns，是波导固有声寿命的4倍。通过理论上的考虑，我们预计该概念可以在实际的实验限制内实现高达微秒的存储时间，同时保持光信号的GHz带宽。