论文标题
超高分辨率和宽带芯片尺度斑点增强了傅立叶变换光谱仪
Ultra-high resolution and broadband chip-scale speckle enhanced Fourier-transform spectrometer
论文作者
论文摘要
硅光子学的最新进展使得能够开发芯片尺度的光子设备用于感应和信号处理应用，其中芯片上的光谱仪特别关注精度波长监测和相关应用。大多数芯片尺度光谱仪都遭受了分辨率带宽权衡，因此限制了设备的用途。在这里，我们报告了一种新型的被动，芯片尺度，混合斑点增强的傅立叶变换装置，该设备在先进的芯片尺度斑点和傅立叶变换光谱仪上表现出两次缩小的技巧（带宽/分辨率）的两种效率。在我们的原始设备中，我们展示了140 MHz的光谱分辨率，带宽为12 nm，以$ 10^4 $的精细度，可以在1500-1600 nm的范围内运行。这种芯片尺度的光谱仪结构实现了典型的空间杂项离散傅立叶变换干涉仪网络，该网络通过晶圆基板生成的斑点增强。后一种效果非常简单，非常简单，将高波长分辨率固有地叠加到由强烈的引导波导产生的斑点，具有更宽带，但分辨率较低，但分辨率较低的离散傅立叶变换模态的总体波导结构。这种混合方法意味着一种新的途径，用于实现能够超高分辨率和宽带性能的芯片尺度光谱仪。
Recent advancements in silicon photonics are enabling the development of chip-scale photonics devices for sensing and signal processing applications, among which on-chip spectrometers are of particular interest for precision wavelength monitoring and related applications. Most chip-scale spectrometers suffer from a resolution-bandwidth trade-off, thus limiting the uses of the device. Here we report on a novel passive, chip-scale, hybrid speckle-enhanced Fourier transform device that exhibits a two order-of-magnitude improvement in finesse (bandwidth/resolution) over the state-of-the art chip-scale speckle and Fourier transform spectrometers. In our proof-of-principle device, we demonstrate a spectral resolution of 140 MHz with 12-nm bandwidth for a finesse of $10^4$ that can operate over a range of 1500-1600 nm. This chip-scale spectrometer structure implements a typical spatial heterodyne discrete Fourier transform interferometer network that is enhanced by speckle generated from the wafer substrate. This latter effect, which is extremely simple to invoke, superimposes the high wavelength resolution intrinsic to speckle generated from a strongly guiding waveguide with a more broadband but lower resolution discrete Fourier transform modality of the overarching waveguide structure. This hybrid approach signifies a new pathway for realizing chip-scale spectrometers capable of ultra-high resolution and broadband performance.
