¹ Beijing Key Laboratory for Precision Optoelectronic Measurement Instrument and Technology, Beijing 100081, China
中国 北京 精密光电测试仪器及技术北京市重点实验室
² School of Optics and Photonics, Beijing Institute of Technology, Beijing 100081, China
中国 北京 北京理工大学光电学院
³ Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
中国 上海 中国科学院 上海光学精密机械研究所
⁴ University of Chinese Academy of Sciences, Beijing 100049, China
中国 北京 中国科学院大学
⁵ National Laboratory of Aerospace Intelligent Control Technology, Beijing 100089, China
中国 北京 宇航智能控制技术全国重点实验室
⁶ Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China
中国 杭州 中国科学院大学 杭州高等研究院
High resolution imaging is achieved using increasingly larger apertures and successively shorter wavelengths. Optical aperture synthesis is an important high-resolution imaging technology used in astronomy. Conventional long baseline amplitude interferometry is susceptible to uncontrollable phase fluctuations, and the technical difficulty increases rapidly as the wavelength decreases. The intensity interferometry inspired by HBT experiment is essentially insensitive to phase fluctuations, but suffers from a narrow spectral bandwidth which results in a lack of effective photons.
In this study, we propose optical synthetic aperture imaging based on spatial intensity interferometry. This not only realizes diffraction-limited optical aperture synthesis in a single shot, but also enables imaging with a wide spectral bandwidth, which greatly improves the optical energy efficiency of intensity interferometry. And this method is insensitive to the optical path difference between the sub-apertures. Simulations and experiments present optical aperture synthesis diffraction-limited imaging through spatial intensity interferometry in a 100 nm spectral width of visible light, whose maximum optical path difference between the sub-apertures reaches 69λ.
This technique is expected to provide a solution for optical aperture synthesis over kilometer-long baselines at optical wavelengths.