eprintid: 10056927 rev_number: 21 eprint_status: archive userid: 608 dir: disk0/10/05/69/27 datestamp: 2018-09-27 10:24:19 lastmod: 2021-11-12 23:54:47 status_changed: 2018-09-27 10:24:19 type: article metadata_visibility: show creators_name: Balakier, K creators_name: Shams, H creators_name: Fice, MJ creators_name: Ponnampalam, L creators_name: Graham, CS creators_name: Renaud, CC creators_name: Seeds, AJ title: Optical Phase Lock Loop as High-Quality Tuneable Filter for Optical Frequency Comb Line Selection ispublished: pub divisions: UCL divisions: B04 divisions: C05 divisions: F46 keywords: Science & Technology, Technology, Physical Sciences, Engineering, Electrical & Electronic, Optics, Telecommunications, Engineering, Microwave photonics, optical filters, optical frequency comb, optical phase lock loop, photonic integration, THz signal generation, tuneable millimetre-wave source component, MICROWAVE PHOTONICS, GENERATION, LASER, MODULATOR, INP, INJECTION, TERAHERTZ, BANDWIDTH, COHERENT note: This work is licensed under a Creative Commons Attribution 3.0 License. For more information, see http://creativecommons.org/licenses/by/3.0/ abstract: This paper describes an optical phase lock loop (OPLL) implemented as an ultraselective optical frequency comb line filter. The OPLL is based on a photonic integrated circuit (PIC) fabricated for the first time through a generic foundry approach. The PIC contains a distributed Bragg reflector (DBR) laser whose frequency and phase are stabilized by reference to an optical frequency comb generator. The OPLL output is a single-mode DBR laser line; other comb lines and noise at the output of the OPLL filter are attenuated by >58 dB below the peak power of the OPLLfilter output line. The OPLL bandwidth is up to 200 MHz, giving a filter quality factor greater than 1,000,000. The DBR laser can be tuned over 1 THz (8 nm), enabling different comb lines to be selected. Locking to a comb line with a frequency offset precisely selectable between 4 and 12 GHz is also possible. The coherence between the DBR laser and the comb lines is demonstrated by measurements of the heterodyne signal residual phase noise level, which is below −100 dBc/Hz at 5 kHz offset from the carrier. The OPLL-filter output can be up to 6 dB higher than the peak power of the comb line to be isolated by the filter. This optical gain is a unique characteristic which can significantly improve the SNR of communication or spectroscopy systems. This OPLL is envisaged to be used for high purity, tuneable microwave, millimetre-wave, and THz generation. date: 2018-10-01 date_type: published publisher: IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC official_url: http://dx.doi.org/10.1109/JLT.2018.2848961 oa_status: green full_text_type: pub language: eng primo: open primo_central: open_green article_type_text: Article verified: verified_manual elements_id: 1565597 doi: 10.1109/JLT.2018.2848961 lyricists_name: Balakier, Katarzyna lyricists_name: Fice, Martyn lyricists_name: Graham, Christopher lyricists_name: Ponnampalam, Lalitha lyricists_name: Renaud, Cyril lyricists_name: Seeds, Alwyn lyricists_name: Shams, Haymen Ahmed Abdelghaffar lyricists_id: KBALA48 lyricists_id: MFICE70 lyricists_id: CGRAH68 lyricists_id: LPONN12 lyricists_id: CRENA49 lyricists_id: AJSEE43 lyricists_id: HELGH05 actors_name: Bracey, Alan actors_id: ABBRA90 actors_role: owner full_text_status: public publication: Journal of Lightwave Technology volume: 36 number: 19 pagerange: 4646-4654 pages: 9 event_location: Tsinghua Univ, Beijing, PEOPLES R CHINA issn: 1558-2213 citation: Balakier, K; Shams, H; Fice, MJ; Ponnampalam, L; Graham, CS; Renaud, CC; Seeds, AJ; (2018) Optical Phase Lock Loop as High-Quality Tuneable Filter for Optical Frequency Comb Line Selection. Journal of Lightwave Technology , 36 (19) pp. 4646-4654. 10.1109/JLT.2018.2848961 <https://doi.org/10.1109/JLT.2018.2848961>. Green open access document_url: https://discovery.ucl.ac.uk/id/eprint/10056927/1/08388199.pdf