Towards integrated photonic interposers for processing octave-spanning microresonator frequency combs  

作　　者：Ashutosh Rao Gregory Moille Xiyuan Lu Daron A.Westly Davide Sacchetto Michael Geiselmann Michael Zervas Scott B.Papp John Bowers Kartik Srinivasan 

机构地区：[1]Physical Measurement Laboratory,Microsystems and Nanotechno logy Division,National Institute of Standards and Technology,Gaithersburg,MD 20899,USA [2]Maryland NanoCenter,University of Maryland,College Park 20742 MD,USA [3]Joint Quantum Institute,NIST/University of Maryland,College Park,MD 20742,USA [4]Ligentec,EPFL Innovation Park,Batiment C,Lausanne,Switzerland [5]Physical Measurement Laboratory,Time and Frequency Division,National Institute of Standards and Technology,Boulder,CO 80305,USA [6]Department of Physics,University of Colorado,Boulder,CO 80309,USA [7]Department of Electrical and Computer Engineering,University of California,Santa Barbara,CA 93106,USA

出　　处：《Light(Science & Applications)》2021年第6期1099-1111,共13页光（科学与应用)（英文版）

基　　金：the Defense Adva need Research Projects Agency(DARPA-DODOS);NIST-UDiversity of Maryland(70NANB10H193);National Institute of Standards and Technology(NIST-on-a-chip).A.R.and X.L.gratefully ack no wledge support un der the Cooperative Research Agreement between the University of Maryland and NIST-CNST,Award no.70NANB10H193.

摘　　要：Microcombs-optical frequency combs generated in microresonators-have advanced tremendously in the past decade,and are advantageous for applications in frequency metrology,navigation,spectroscopy,telecommunications,and microwave photonics.Crucially,microcombs promise fully integrated miniaturized optical systems with unprecedented reductions in cost,size,weight,and power.However,the use of bulk free-space and fiber-optic comp on ents to process microcombs has restricted form factors to the table-top.Taking microcomb-based optical frequency synthesis around 1550 nm as our target application,here,we address this challenge by proposing an integrated photonics interposer architecture to replace discrete components by collecting,routing,and interfacing octave-wide microcomb-based optical signals between photonic chiplets and heterogeneously integrated devices.Experimentally,we con firm the requisite performa nee of the individual passive elements of the proposed interposer一octave-wide dichroics,multimode interferometers,and tunable ring filters,and implement the octave-spanning spectral filteri ng of a microcomb,central to the in terposer,using silicon n itride phot onics.Moreover,we show that the thick silicon nitride needed for bright dissipative Kerr soliton generation can be integrated with the comparatively thin silicon nitride interposer layer through octave-bandwidth adiabatic evanescent coupling,indicating a path towards future system-level consolidation.Fin ally,we numerically confirm the feasibility of operating the proposed in terposer synthesizer as a fully assembled system.Our interposer architecture addresses the immediate need for on-chip microcomb processing to successfully miniaturize microcomb systems and can be readily adapted to other metrology-grade applications based on optical atomic clocks and high-precision navigation and spectroscopy.

关 键 词：RESONATOR INTERFEROMETER SYNTHESIZER 

分 类 号：O43[机械工程—光学工程]