Acousto-optic interactions involving propagating phonons can break the time-reversal and frequency-modulation symmetry of light. However, conventional acousto-optic modulators based on bulk materials have a modulation frequency limited to hundreds of megahertz due to their large structural sizes. Here, we experimentally demonstrate gigahertz single-sideband acousto-optic modulation on an etchless lithium niobate integrated platform. The upper- or lower-sideband modulation of light can be obtained conveniently by choosing specific combinations of input and output channels. Under this scheme, we have realized a 3 GHz frequency shifter, which operates in the C-band with a 3 dB bandwidth of ∼35 nm. The extinction ratios of the upper(lower)-sideband modulated light to the lower(upper)-sideband modulated and unmodulated light are >44 (47) and 25 (23) dB in the 3 dB operating bandwidth. The frequency-shifted light can be further processed with amplitude and frequency modulation. Therefore, the demonstrated gigahertz single-sideband acousto-optic modulation can enable many photonic applications such as optical signal processing, sensing, and ion trapping.

中文翻译：

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无蚀刻铌酸锂集成平台上的千兆赫声光调制和频移

涉及传播声子的声光相互作用会破坏光的时间反转和频率调制对称性。然而，基于大块材料的常规声光调制器由于其大的结构尺寸而具有限于数百兆赫兹的调制频率。在这里，我们通过实验演示了在无蚀刻铌酸锂集成平台上的千兆赫兹单边带声光调制。通过选择输入和输出通道的特定组合，可以方便地获得光的上边带或下边带调制。在这种方案下，我们实现了一个3 GHz移频器，该移频器在C波段工作，具有约35 nm的3 dB带宽。上（下）边带调制光与下（上）边带调制和未调制光的消光比> 3 dB工作带宽中的44（47）和25（23）dB。移频后的光可以通过幅度和频率调制进行进一步处理。因此，已证明的千兆赫兹单边带声光调制技术可以实现许多光子应用，例如光信号处理，传感和离子捕获。