Non-reciprocal interband Brillouin modulation
Non-reciprocal interband Brillouin modulation
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DOI：
10.1038/s41566-018-0254-9
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发表时间：
2018-10-01
期刊：
影响因子：
35
通讯作者：
Rakich, Peter T.
中科院分区：
文献类型：
--
作者：
Kittlaus, Eric A.;Otterstrom, Nils T.;Rakich, Peter T.
在光子系统中，光的非互易传播是控制光串扰和后向散射的关键。然而，在低损耗集成光子电路中实现高保真的非互易仍然是一个挑战。在这里，我们通过实验证明了一种非局部声光散射形式，可以在集成硅光子平台中产生非互反的单边带调制和模式转换。在该系统中，由硅波导中的光力驱动的行波声子通过线性带间布里渊散射在时空上调制单独波导中的光。该过程将基于窄带光力学的非互易方案扩展到行波物理，实现超过125 GHz的大操作带宽和前向和后向传播光波之间高达38 dB的非互易对比度。通过改变光驱波长，调制器工作波长可在35纳米范围内调节。这种行波声光相互作用为实现集成光子学中的宽带、低损耗隔离器和环行器提供了一条有希望的途径。
Non-reciprocal light propagation is essential to control optical crosstalk and back-scatter in photonic systems. However, realizing high-fidelity non-reciprocity in low-loss integrated photonic circuits remains challenging. Here, we experimentally demonstrate a form of non-local acousto-optic light scattering to produce non-reciprocal single-sideband modulation and mode conversion in an integrated silicon photonic platform. In this system, a travelling-wave acoustic phonon driven by optical forces in a silicon waveguide spatiotemporally modulates light in a separate waveguide through linear interband Brillouin scattering. This process extends narrowband optomechanics-based schemes for non-reciprocity to travelling-wave physics, enabling large operation bandwidths of more than 125 GHz and up to 38 dB of non-reciprocal contrast between forward- and backward-propagating optical waves. The modulator operation wavelength is tunable over a 35-nm range by varying the optical drive wavelength. Such travelling-wave acousto-optic interactions provide a promising path toward the realization of broadband, low-loss isolators and circulators within integrated photonics.