Broadband picometer-scale resolution on-chip spectrometer with reconfigurable photonics  

作　　者：Chunhui Yao Minja Chen Ting Yan Liang Ming Qixiang Cheng Richard Penty 

机构地区：[1]Centre for Photonic Systems,Electrical Engineering Division,Department of Engineering,University of Cambridge,Cambridge CB3 OFA,UK [2]GlitterinTech Limited,Xuzhou 221000,China

出　　处：《Light(Science & Applications)》2023年第7期1415-1424,共10页光（科学与应用)（英文版）

基　　金：supported by UK EPSRC,project QUDOS(EP/TO28475/1);The authors thank CORNERSTONE for providing free access to their first SiN MPW run(funded by the CORNERSTONE 2 project under Grant EP/TO19697/1).

摘　　要：Miniaturization of optical spectrometers is important to enable spectroscopic analysis to play a role in in situ,or even in vitro and in vivo characterization systems.However,scaled-down spectrometers generally exhibit a strong trade-off between spectral resolution and operating bandwidth,and are often engineered to identify signature spectral peaks only for specific applications.In this paper,we propose and demonstrate a novel global sampling strategy with distributed filters for generating ultra-broadband pseudo-random spectral responses.The geometry of all-pass ring filters is tailored to ensure small self-and cross-correlation for effective information acquisition across the whole spectrum,which dramatically reduces the requirement on sampling channels.We employ the power of reconfigurable photonics in spectrum shaping by embedding the engineered distributed filters.Using a moderate mesh of MZls,we create 256 diverse spectral responses on a single chip and demonstrate a resolution of 20 pm for single spectral lines and 30 pm for dual spectral lines over a broad bandwidth of 115 nm,to the best of our knowledge achieving a new record of bandwidth-to-resolution ratio.Rigorous simulations reveal that this design will readily be able to achieve single-picometer-scale resolution.We further show that the reconfigurable photonics provides an extra degree of programmability,enabling user-defined features on resolution,computation complexity,and relative error.The use of SiN integration platform enables the spectrometer to exhibit excellent thermal stability of±2.0℃,effectively tackling the challenge of temperature variations at picometer-scale resolutions.

关 键 词：RECONFIGURABLE RESOLUTION enable 

分 类 号：O4[理学—物理]