Exact time-reversal focusing of acoustic and quantum excitations in open cavities: The perfect inverse filter
Exact time-reversal focusing of acoustic and quantum excitations in open cavities: The perfect inverse filter
复制标题
开放腔中声学和量子激发的精确时间反转聚焦：完美的逆滤波器
DOI：
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发表时间：
2010
期刊：
影响因子：
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通讯作者：
H. Pastawski
中科院分区：
文献类型：
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作者：
H. L. Calvo;H. Pastawski
时间反转镜 (TRM) 规定信号的反向回放，以将声学激励聚焦为洛施密特回波。在量子域中，完美逆滤波器 (PIF) 处理该信号，以确保精确反转，前提是激励源自换能器界定的腔体外部。我们证明，当在该腔体内产生初始激励时，PIF 采取简单的形式。这也适用于声学案例，它可以纠正 TRM 并改进声学火箭筒的设计。我们解决了模拟量子火箭筒的开放混沌腔和亥姆霍兹谐振器的简单模型，表明 PIF 对于补偿高度局部激发中涉及的群速度和实现亚波长分辨率至关重要。
The time-reversal mirror (TRM) prescribes the reverse playback of a signal to focalize an acoustic excitation as a Loschmidt echo. In the quantum domain, the perfect inverse filter (PIF) processes this signal to ensure an exact reversion provided that the excitation originated outside the cavity delimited by the transducers. We show that PIF takes a simple form when the initial excitation is created inside this cavity. This also applies to the acoustical case, where it corrects the TRM and improves the design of an acoustic bazooka. We solve an open chaotic cavity modeling a quantum bazooka and a simple model for a Helmholtz resonator, showing that the PIF becomes decisive to compensate the group velocities involved in a highly localized excitation and to achieve subwavelength resolution.