Optical spectrometry is a tool to investigate wavelength-dependent light–matter interactions and is widely used in astronomy, physics and chemistry. Integration and miniaturization of the currently bulky spectrometers will have an impact on applications where compactness and low complexity are key, such as air- and spaceborne missions. A high-resolution spectroscopy principle based on the near-field detection of a spatial standing wave inside a subwavelength waveguide has shown great promise to accomplish some of the aforementioned demands. However, small-scale devices based on this principle face strong bandwidth limitations due to undersampling of the standing wave. Here, we demonstrate an integrated single-waveguide Fourier transform spectrometer with an operational bandwidth of 500 nm in the near- and short-wavelength infrared, not relying on any moving components. The prototype device, with a footprint of less than 10 mm², exploits the electro-optic properties of thin-film lithium niobate in order to retrieve the complete spatial interferogram.

光谱法是研究与波长有关的光-物质相互作用的工具，广泛用于天文学，物理学和化学领域。当前体积庞大的光谱仪的集成和小型化将对紧凑和低复杂度至关重要的应用产生影响，例如空中和太空飞行任务。基于亚波长波导内部空间驻波的近场检测的高分辨率光谱原理已显示出实现上述某些要求的巨大希望。但是，基于此原理的小型设备由于驻波的欠采样而面临强大的带宽限制。在这里，我们演示了集成的单波导傅里叶变换光谱仪，其在近波长和短波长红外中的工作带宽为500 nm，不依赖任何移动组件。原型设备，占地面积小于10毫米^{如图2所示}，利用薄膜铌酸锂的电光特性来检索完整的空间干涉图。