近日，深圳国际量子研究院的刘骏秋及其研究团队取得一项新进展。经过不懈努力，他们研制出用于集成光子学的宽带高分辨率矢量频谱分析仪。相关研究成果已于2024年4月8日在国际知名学术期刊《光：科学与应用》上发表。

该研究团队创新性地展示了一款矢量频谱分析仪（VSA），它能够在单次设置中全面表征无源器件和有源激光源。这款双模VSA不仅能够精准测量无源器件的损耗、相位响应及色散特性，还具备将宽带激光光谱相干映射至射频域的能力。值得一提的是，该VSA拥有高达55.1THz（1260-1640nm）的带宽，频率分辨率达到471kHz，动态范围达56dB。同时，这款基于光纤的VSA结构紧凑、稳定。它既不需要高速调制器和光电探测器，也不需要任何主动反馈控制。

最后，研究人员成功将VSA应用于集成色散波导的表征、频率梳谱的映射以及相干光探测和测距（LiDAR）等领域。本研究的VSA为器件分析和激光光谱学提供了一种创新的方法，有望在未来的光子系统以及传感、通信、成像和量子信息处理等领域发挥关键作用。

据悉，对光谱的分析——发射或吸收——被认为是发现和理解物质的最有力的方法。各种光谱仪的发明和发展为人们提供了多功能的超灵敏诊断工具，用于痕量气体检测，同位素分析，以及解析原子和分子的超精细结构。随着数据和信息的激增，人们对频谱分析提出了迫切而苛刻的要求，频谱带宽和频率分辨率不断提高。这些要求对于携带大量信息的宽带激光源和用于信息处理系统的色散器件尤其严格。此外，频谱分析仪有望探测设备的相位响应，其中额外的信息被编码。

附：英文原文

Title: A wideband, high-resolution vector spectrum analyzer for integrated photonics

Author: Luo, Yi-Han, Shi, Baoqi, Sun, Wei, Chen, Ruiyang, Huang, Sanli, Wang, Zhongkai, Long, Jinbao, Shen, Chen, Ye, Zhichao, Guo, Hairun, Liu, Junqiu

Issue&Volume: 2024-04-08

Abstract: The analysis of optical spectra—emission or absorption—has been arguably the most powerful approach for discovering and understanding matter. The invention and development of many kinds of spectrometers have equipped us with versatile yet ultra-sensitive diagnostic tools for trace gas detection, isotope analysis, and resolving hyperfine structures of atoms and molecules. With proliferating data and information, urgent and demanding requirements have been placed today on spectrum analysis with ever-increasing spectral bandwidth and frequency resolution. These requirements are especially stringent for broadband laser sources that carry massive information and for dispersive devices used in information processing systems. In addition, spectrum analyzers are expected to probe the device’s phase response where extra information is encoded. Here we demonstrate a novel vector spectrum analyzer (VSA) that is capable of characterizing passive devices and active laser sources in one setup. Such a dual-mode VSA can measure loss, phase response, and dispersion properties of passive devices. It also can coherently map a broadband laser spectrum into the RF domain. The VSA features a bandwidth of 55.1THz (1260–1640nm), a frequency resolution of 471kHz, and a dynamic range of 56dB. Meanwhile, our fiber-based VSA is compact and robust. It requires neither high-speed modulators and photodetectors nor any active feedback control. Finally, we employ our VSA for applications including characterization of integrated dispersive waveguides, mapping frequency comb spectra, and coherent light detection and ranging (LiDAR). Our VSA presents an innovative approach for device analysis and laser spectroscopy, and can play a critical role in future photonic systems and applications for sensing, communication, imaging, and quantum information processing.

DOI: 10.1038/s41377-024-01435-z

Source: https://www.nature.com/articles/s41377-024-01435-z