Micro-combs: A novel generation of optical sources
Authors: Pasquazi A., Peccianti M., Razzari L., Moss D.J., Coen S., Erkintalo M., Chembo Y.K., Hansson T., Wabnitz S., Del
Autors Affiliation: EMT, INRS, 1650 Blvd Lionel Boulet, Varennes, PQ J3X 1S2, Canada; Univ Sussex, Dept Phys & Astron, Brighton BN1 9QH, E Sussex, England; Swinburne Univ Technol, Ctr Microphoton, Hawthorn, Vic 3122, Australia; Univ Auckland, Dodd Walls Ctr Photon & Quantum Technol, Dept Phys, Auckland 1142, New Zealand; Univ Bourgogne Franche Comte, FEMTO ST Inst, CNRS, Opt Dept, 15B Ave Montboucons, F-25030 Besancon, France; GeorgiaTech, CNRS, Joint Int Lab, UMI 29581,Sch Elect & Comp Engn, Atlanta Mirror Site,777 Atlantic Dr NW, Atlanta, GA 30332 USA; Univ Brescia, Dipartimento Ingn Informaz, Via Branze 38, I-25123 Brescia, Italy; CNR, INO, Via Branze 38, I-25123 Brescia, Italy; Natl Phys Lab, Teddington TW11 0LW, Middx, England; Purdue Univ, Sch Elect & Comp Engn, 465 Northwestern Ave, W Lafayette, IN 47907 USA; Tsinghua Univ, Dept Elect Engn, Beijing 100084, Peoples R China; Univ Elect Sci & Technol China, Inst Fundamental & Frontier Sci, Chengdu 610054, Sichuan, Peoples R China; Natl Res Univ Informat Technol Mech & Opt, St Petersburg, Russia
Abstract: The quest towards the integration of ultra-fast, high-precision optical clocks is reflected in the large number of high-impact papers on the topic published in the last few years. This interest has been catalysed by the impact that high-precision optical frequency combs (OFCs) have had on metrology and spectroscopy in the last decade [1-5]. OFCs are often referred to as optical rulers: their spectra consist of a precise sequence of discrete and equally-spaced spectral lines that represent precise marks in frequency. Their importance was recognised worldwide with the 2005 Nobel Prize being awarded to T.W. Hansch and J. Hall for their breakthrough in OFC science . They demonstrated that a coherent OFC source with a large spectrum – covering at least one octave – can be stabilised with a self-referenced approach, where the frequency and the phase do not vary and are completely determined by the source physical parameters. These fully stabilised OFCs solved the challenge of directly measuring optical frequencies and are now exploited as the most accurate time references available, ready to replace the current standard for time. Very recent advancements in the fabrication technology of optical micro-cavities [61 are contributing to the development of OFC sources. These efforts may open up the way to realise ultra-fast and stable optical clocks and pulsed sources with extremely high repetition-rates, in the form of compact and integrated devices. Indeed, the fabrication of high-quality factor (high-Q) micro-resonators, capable of dramatically amplifying the optical field, can be considered a photonics breakthrough that has boosted not only the scientific investigation of OFC sources [7-13] but also of optical sensors and compact light modulators [6,14].
In this framework, the demonstration of planar high-Q resonators, compatible with silicon technology [10-14], has opened up a unique opportunity for these devices to provide entirely new capabilities for photonic-integrated technologies. Indeed, it is well acknowledged by the electronics industry that future generations of computer processing chips will inevitably require an extremely high density of copper-based interconnections, significantly increasing the chip power dissipation to beyond practical levels [15-17]; hence, conventional approaches to chip design must undergo radical changes. On-chip optical networks, or optical interconnects, can offer high speed and low energy per transferred-bit, and micro-resonators are widely seen as a key component to interface the electronic world with photonics.
Many information technology industries have recently focused on the development of integrated ring resonators to be employed for electrically-controlled light modulators [ 1417], greatly advancing the maturity of micro-resonator technology as a whole. Recently [11-13], the demonstration of OFC sources in micro-resonators fabricated in electronic (i.e. in complementary metal oxide semiconductor (CMOS)) compatible platforms has given micro-cavities an additional appeal, with the possibility of exploiting them as light sources in microchips. This scenario is creating fierce competition in developing highly efficient OFC generators based on micro-cavities which can radically change the nature of information transport and processing. Even in telecommunications, perhaps a more conventional environment for optical technologies, novel time-division multiplexed optical systems will require extremely stable optical clocks at ultra-high pulse repetition-rates towards the THz scale. Furthermore, arbitrary pulse generators based on OFC [18,19] are seen as one of the most promising solutions for this next generation of high-capacity optical coherent communication systems. This review will summarise the recent exciting achievements in the field of micro-combs, namely optical frequency combs based on high-Q micro resonators, with a perspective on both the potential of this technology, as well as the open questions and challenges that remain.
Journal/Review: PHYSICS REPORTS-REVIEW SECTION OF PHYSICS LETTERS
Volume: 729 Pages from: 1 to: 81
More Information: A.P. and M.P. acknowledge the support of the U.K. Quantum Technology Hub for Sensors and Metrology, EPSRC, under Grant EP/M013294/1, of the Marie Curie Action MC-CIG and IIF REA grant 630833 and 327627. L.R. is grateful for financial support from the Natural Sciences and Engineering Research Council (NSERC) of Canada. D.M. acknowledges support from Australian Research Council Discovery Projects scheme (DP150104327). M.E. acknowledges support from the Marsden Fund and the Rutherford Discovery Fellowships of the Royal Society of New Zealand.
Y.K.C. would like to acknowledge funding from the European Research Council (ERC) through the projects NextPhase (StG 278616) & Versyt (PoC 632108), from the Centre National d\’Etudes Spatiales (CNES) through the project SHYRO and from the Labex ACTION. T.H. and S.W. acknowledge support from Ministero dell\’Istruzione, dell\’Universita e della Ricerca (MIUR) (PRIN-2015KEZNYM). X.X. and A.M.W. acknowledge funding from National Science Foundation under grant ECCS-1509578, by the Air Force Office of Scientific Research under grant FA9550-15-1-0211 and by the DARPA PULSE program through grant W31P40-131-0018 from AMRDEC. X.X. is also supported by the National Natural Science Foundation of China under grant 6169190011, 6169190012, 61420106003 and the Beijing Natural Science Foundation under grant 4172029. R.M. acknowledges support by the Natural Sciences and Engineering Research Council of Canada (NSERC) through the Steacie (411724-2011), Strategic (STPGP 478876-15), Discovery (RGPIN-2014-06093) and Acceleration (462548-2014) Grants Schemes, by the MESI PSR-SIIRI Initiative (PSR-SARI-952) in Quebec and by the Canada Research Chair Program (95023138). Furthermore, he is grateful for additional support from the Government of the Russian Federation through the ITMO Fellowship and Professorship Program (grant 074-U 01) and from the 1000 Talents Sichuan Program in China.DOI: 10.1016/j.physrep.2017.08.004Citations: 209data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2021-10-24References taken from IsiWeb of Knowledge: (subscribers only)Connecting to view paper tab on IsiWeb: Click hereConnecting to view citations from IsiWeb: Click here