{"67735":{"#nid":"67735","#data":{"type":"news","title":"New Microspectrometer Design Achieves High Resolution, Wide Bandwidth","body":[{"value":"\u003Cp\u003EA new microspectrometer architecture that uses compact disc-shaped resonators could address the challenges of integrated lab-on-chip sensing systems that now require a large off-chip spectrometer to achieve high resolution.\u003C\/p\u003E\n\u003Cp\u003ESpectrometers have conventionally been expensive and bulky bench-top instruments used to detect and identify the molecules inside a sample by shining light on it and measuring different wavelengths of the emitted or absorbed light. Previous efforts toward miniaturizing spectrometers have reduced their size and cost, but these reductions have typically resulted in lower-resolution instruments.\n\u003C\/p\u003E\n\u003Cp\u003E\u0022For spectrometers, it is better to be small and cheap than big and bulky -- provided that the optical performance targets are met,\u0022 said Ali Adibi, a professor in the School of Electrical and Computer Engineering at the Georgia Institute of Technology. \u0022We were able to achieve high resolution and wide bandwidth with a compact single-mode on-chip spectrometer through the use of an array of microdonut resonators, each with an outer radius of two microns.\u0022 \n\u003C\/p\u003E\n\u003Cp\u003EThe 81-channel on-chip spectrometer designed by Georgia Tech engineers achieved 0.6-nanometer resolution over a spectral range of more than 50 nanometers with a footprint less than one square millimeter. The simple instrument -- with its ultra-small footprint -- can be integrated with other devices, including sensors, optoelectronics, microelectronics and microfluidic channels for use in biological, chemical, medical and pharmaceutical applications.\n\u003C\/p\u003E\n\u003Cp\u003EThe microspectrometer architecture was described in a paper published in the June 20 issue of the journal \u003Cem\u003EOptics Express\u003C\/em\u003E. The research was supported by the Air Force Office of Scientific Research and the Defense Advanced Research Projects Agency.\u003C\/p\u003E\n\u003Cp\u003E\u0022This architecture is promising because the quality-factor of the microdonut resonators is higher than that of microrings of the same size,\u0022 said Richard Soref, a research scientist in the U.S. Air Force Research Laboratory at Hanscom Air Force Base who was not directly involved in the research. \u0022Having such small resonators is also an advantage because they can be densely packed on a chip, enabling a large spectrum to be sampled.\u0022 \n\u003C\/p\u003E\n\u003Cp\u003EAdibi\u0027s group is currently developing the next generation of these spectrometers, which are being designed to contain up to 1000 resonators and achieve 0.15-nanometer resolution with a spectral range of 150 nanometers and footprint of 200 micrometers squared.\n\u003C\/p\u003E\n\u003Cp\u003EAdibi, current graduate student Zhixuan Xia and research engineer Ali A. Eftekhar, and former research engineers Babak Momeni and Siva Yegnanarayanan designed and implemented the microspectrometer using CMOS-compatible fabrication processes. The key building element they used to construct the device was an array of miniaturized microdonut resonators, which were essentially microdiscs perforated in their centers. This research built on former Georgia Tech graduate student Mohammad Soltani\u0027s work to develop miniature microresonators, which was published in the Sept. 13, 2010 issue of the journal \u003Cem\u003EOptics Express\u003C\/em\u003E.\u003C\/p\u003E\n\u003Cp\u003EThe researchers adjusted the resonance wavelengths of different microdonut resonators by engineering their geometry. While the resonance was very sensitive to variations in the outer radius, fine-tuning could be achieved by adjusting the inner radius. The microdonut resonators were carefully designed so that each of the resonators only tapped a small portion of the incoming spectrum, thus enabling measurement of the entire spectrum of desired wavelengths in real time. \n\u003C\/p\u003E\n\u003Cp\u003EA key advantage of this microspectrometer design, according to the researchers, is the ability to independently control and configure the resolution and operating bandwidth of each channel for different applications. The device can cover a wide range of wavelengths from approximately one to three micrometers. Extending this concept to the silicon nitride platform also enables spectrometers for visible light applications.\n\u003C\/p\u003E\n\u003Cp\u003E\u0022The microspectrometer we designed may allow individuals to replace the big, bulky, high- resolution spectrometers with a large bandwidth they are currently using with an on-chip spectrometer the size of a penny,\u0022 noted Adibi. \u0022Our device has the potential to be a high-resolution, lightweight, compact, high-speed and versatile microspectrometer with a large dynamic range that can be used for many applications.\u0022\n\u003C\/p\u003E\n\u003Cp\u003ECurrent graduate students Qing Li and Maysamreza Chamanzar also contributed to this work.\n\u003C\/p\u003E\n\u003Cp\u003E\u003Cem\u003EThis research was supported by the Defense Advanced Research Projects Agency (DARPA) (Award No. HR 0011-10-1-0075) and the Air Force Office of Scientific Research (AFOSR) (Award No. FA9550-06-01-2003). The content is solely the responsibility of the principal investigator and does not necessarily represent the official views of DARPA or AFOSR.\u003C\/em\u003E\n\u003C\/p\u003E\n\u003Cp\u003E\u003Cstrong\u003EResearch News \u0026amp; Publications Office\u003Cbr \/\u003E\nGeorgia Institute of Technology\u003Cbr \/\u003E\n75 Fifth Street, N.W., Suite 314\u003Cbr \/\u003E\nAtlanta, Georgia  30308  USA\u003C\/strong\u003E\n\u003C\/p\u003E\n\u003Cp\u003E\u003Cstrong\u003EMedia Relations Contacts:\u003C\/strong\u003E Abby Robinson (abby@innovate.gatech.edu; 404-385-3364) or John Toon (jtoon@gatech.edu; 404-894-6986)\n\u003C\/p\u003E\n\u003Cp\u003E\u003Cstrong\u003EWriter:\u003C\/strong\u003E Abby Robinson\u003C\/p\u003E","summary":null,"format":"limited_html"}],"field_subtitle":"","field_summary":[{"value":"\u003Cp\u003EGeorgia Tech electrical engineers have designed a new microspectrometer architecture using compact doughnut-shaped resonators that achieves high resolution and wide bandwidth.\u003C\/p\u003E","format":"limited_html"}],"field_summary_sentence":[{"value":"New microspectrometer architecture uses compact disc-shaped resonators"}],"uid":"27206","created_gmt":"2011-06-20 00:00:00","changed_gmt":"2016-10-08 03:08:53","author":"Abby Vogel Robinson","boilerplate_text":"","field_publication":"","field_article_url":"","dateline":{"date":"2011-06-20T00:00:00-04:00","iso_date":"2011-06-20T00:00:00-04:00","tz":"America\/New_York"},"extras":[],"hg_media":{"67736":{"id":"67736","type":"image","title":"Microspectrometer micrograph","body":null,"created":"1449177176","gmt_created":"2015-12-03 21:12:56","changed":"1475894592","gmt_changed":"2016-10-08 02:43:12"},"67737":{"id":"67737","type":"image","title":"Microdonut resonator SEM image","body":null,"created":"1449177176","gmt_created":"2015-12-03 21:12:56","changed":"1475894592","gmt_changed":"2016-10-08 02:43:12"},"67738":{"id":"67738","type":"image","title":"Experimental setup","body":null,"created":"1449177176","gmt_created":"2015-12-03 21:12:56","changed":"1475894592","gmt_changed":"2016-10-08 02:43:12"}},"media_ids":["67736","67737","67738"],"related_links":[{"url":"http:\/\/dx.doi.org\/10.1364\/OE.19.012356","title":"June 20 Optics Express paper"},{"url":"http:\/\/www.ece.gatech.edu\/about\/personnel\/bio.php?id=2","title":"Ali Adibi"},{"url":"http:\/\/www.ece.gatech.edu\/","title":"School of Electrical and Computer Engineering"}],"groups":[{"id":"1188","name":"Research Horizons"}],"categories":[{"id":"145","name":"Engineering"},{"id":"135","name":"Research"},{"id":"150","name":"Physics and Physical Sciences"}],"keywords":[{"id":"2769","name":"Ali Adibi"},{"id":"13444","name":"cmos fabrication"},{"id":"594","name":"college of engineering"},{"id":"1925","name":"Electrical and Computer Engineering"},{"id":"7343","name":"lab-on-a-chip"},{"id":"13441","name":"microspectrometer"},{"id":"13443","name":"on-chip spectrometer"},{"id":"13442","name":"Resonator"},{"id":"169408","name":"spectrometer"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[],"invited_audience":[],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[{"value":"\u003Cp\u003E\u003Cstrong\u003EAbby Robinson\u003C\/strong\u003E\u003Cbr \/\u003EResearch News and Publications\u003Cbr \/\u003E\u003Ca href=\u0022http:\/\/www.gatech.edu\/contact\/index.html?id=avogel6\u0022\u003EContact Abby Robinson\u003C\/a\u003E\u003Cbr \/\u003E\u003Cstrong\u003E404-385-3364\u003C\/strong\u003E\u003C\/p\u003E","format":"limited_html"}],"email":["abby@innovate.gatech.edu"],"slides":[],"orientation":[],"userdata":""}}}