UCSB Engineering

Nadir Dagli


Electrical & Computer Engineering

Nadir Dagli


ECE Department
University of California
Santa Barbara, CA 93106

tel: 805 893 4847
fax: 805 893 3262

Compact optical resonator based on TIR Mirrors

Compact optical resonator based on TIR Mirrors

Research Description

Professor Dagli’s current interests are design, fabrication and modeling of guided-wave components for optical integrated circuits, ultra fast electro-optic GaAs/AlGaAs optical modulators, WDM components and photonic nanostructures. During the course of his career he and his students were the first to develop finite difference beam propagation method widely used in commercial optical simulation and modeling software. His group also developed novel compound semiconductor electro-optic modulators with electrical bandwidths exceeding 40 GHz with drive voltages of less than 5 V for 1 cm long electrode using the substrate removal technology. Compound semiconductor electro-optic modulators with drive voltages as low as 0.3 V for 0.7 cm long electrode were also recently developed by his group using substrate removed photonic nanowires. He is also currently working on very compact ring resonators and their novel applications. Recent results include compact tunable ring resonators based on deeply etched total internal reflection mirrors integrated with semiconductor optical amplifiers and compact ring lasers folded by total internal reflection mirrors.

His past research efforts include calculation of the optical and transport properties of quantum wires including valence band mixing effects, experimental study of single and coupled electron waveguides, millimeter-wave heterojunction bipolar transistors with negative output resistance, study of wave effects in high speed GaAs digital integrated circuits, growth and characterization of InP and InGaAsP epitaxial layers and X band IMPATT diode oscillators.


Nadir Dagli received the B.S. and M.S. degrees in electrical engineering from Middle East Technical University, Ankara, Turkey on 1976 and 1979, respectively, and the Ph.D. degree, also in electrical engineering, from Massachusetts Institute of Technology, Cambridge, MA on December 1986. After graduation he joined the electrical and computer engineering department at University of California at Santa Barbara on January 1987, where he is currently a Professor. Dr. Dagli chaired and served on the technical program committees and advisory committees of many leading conferences such as CLEO, CLEO Pacific Rim, IEEE Lasers and Electro Optics Society Annual Meeting, IEEE International Topical Meeting on Microwave Photonics, OSA Integrated Photonic and Nanophotonics Research and Applications topical meeting, SPIE Photonics West and SPIE International Symposium on Microtechnologies for the New Millennium. He served as a member of editorial board of IEEE Transactions on Microwave Theory and Techniques, 1994-1998. Professor Dagli was the Associate Editor for IEEE Photonics Technology Letters from 1997 to 2000 and the Editor-in-Chief of IEEE Photonics Technology Letters 2000-2005. He authored and coauthored over 150 refereed journal and conference publications, several book chapters as well an edited book entitled “High Speed Photonic Devices” Published by Taylor and Francis.


  • IEEE Fellow, 2006
  • Elected member of the IEEE-LEOS Board of Governors, 2003-2005
  • UCSB College of Engineering Outstanding Faculty Member Award, 1997-1998
  • UC Regents Junior Faculty Fellowship, 1989-1990
  • UCSB Alumni Association Distinguished Teaching Award, 1989-1990
  • IBM Predoctoral Fellowship, 1983-1984
  • NATO Science Fellowship, 1979-1981

Selected Publications

  • 0.3 V Drive Voltage GaAs/AlGaAs Substrate Removed Mach-Zehnder Intensity Modulators, Appl. Phys. Lett., vol.92, 2008, 201103, JaeHyuk Shin, Yu-Chia Chang, and Nadir Dagli
  • Electro-optic and electro-absorption characterization of InAs quantum dot waveguides, Opt. Express, vol. 16, No. 5, 2008, pp. 3439-3444, I. B. Akca, A. Dana, A. Aydinli, M. Rossetti, L. Li, A. Fiore, and N. Dagli
  • 35 GHz Bandwidth, 5 V-cm Drive Voltage, Bulk GaAs Substrate Removed Electro Optic Modulators, IEEE Photonics Technology Letters, vol. 19, 2007, JaeHyuk Shin, Shaomin Wu, and Nadir Dagli.
  • Compact rectangular ring resonator with optimum multimode interference, Japanese Journal of Applied Physics Part 2, Vol. 46, No. 41-44, 2007, pp. 1019-1021, Doo Gun Kim, Wah Choi Young, Jong Chang Yi and Nadir Dagli
  • Micro ring cavity resonator incorporating total internal reflection mirrors, Proc. SPIE 6475, 64750Y, 2007, Doo Gun Kim, Woon Kyung Choi, Young Wan Choi, Jong Chang Yi, Youngchul Chung, and Nadir Dagli
  • Multimode-interference-coupled ring resonators based on total-internal-reflection mirrors, Japanese Journal Of Applied Physics Part 1-Regular Papers Brief Communications and Review Papers, vol. 46, No.1, 2007, pp. 175-181, Doo Gun Kim, Young Wan Choi, Jong Chang Yi, Youngchul Chung, Cem Ozturk and Nadir Dagli.
  • Rectangular Ring Lasers based on Total Reflection Mirrors and Three Waveguide Couplers, IEEE Photonics Technology Letters, vol.19, no. 5, 2007, pp. 306-308, Doo Gun Kim, Jae Hyuk Shin, Cem Ozturk, Jong Chang Yi, Youngchul Chung and Nadir Dagli.
  • Bulk undoped GaAs-AlGaAs substrate-removed electrooptic modulators with 3.7-V-cm drive voltage at 1.55 micrometer, IEEE Photonics Technology Letters, vol.18, no. 21, 2006, pp. 2251-2253, Jae Hyuk Shin, Shaomin Wu and Nadir Dagli.
  • Low-power thermo-optical tuning of SOI resonator switch, IEEE Photonics Technology Letters, vol.18, no.2, 2006, pp. 364-366, I. Kiyat, A. Aydinli and N. Dagli.
  • Reflection Properties of Coupled-Ring Reflectors, IEEE/OSA J. of Lightwave Technology, vol. 24, No. 4, 2006, pp. 1865-1874, Youngchul Chung, Doo-Gun Kim, and Nadir Dagli.
  • A compact silicon-on-insulator polarization splitter, IEEE Photonics Technology Letters, vol.17, no.1, 2005, pp.100-102, I. Kiyat, A. Aydinli and N. Dagli.
  • High-Q silicon-on-insulator optical rib waveguide racetrack resonators, Optics Express, vol. 13, No. 6, 2005, pp. 1900-1905, I. Kiyat, A. Aydinli and N. Dagli.
  • Novel T-Rail Electrodes for Substrate Removed Low-Voltage, High-Speed GaAs/AlGaAs Electro-optic Modulators, IEEE Trans. Microwave Theory Tech., vol. MTT-53, No. 2, 2005, pp. 636 – 643, J. H. Shin, C. Ozturk, S. R. Sakamoto, Y. J. Chiu and N. Dagli.
  • Polarization Characteristics of Compact SOI Rib Waveguide Racetrack Resonators, IEEE Photonics Technology Letters, vol.17, no.10, 2005, pp. 2098-3000, I. Kiyat, A. Aydinli and N. Dagli.
  • Total Internal Reflection Mirror based InGaAsP Ring Resonators Integrated with Optical Amplifiers, IEEE Photonics Technology Letters, vol.17, no.9, 2005, pp. 1899-1901, Doo Gun Kim, Jae Hyuk Shin, Cem Ozturk, Jong Chang Yi, Youngchul Chung and Nadir Dagli.
  • Widely Tunable Coupled-Ring Reflector Laser Diode, IEEE Photonics Technology Letters, vol.17, no.9, 2005, pp. 1773-1775, Youngchul Chung, Doo-Gun Kim, and Nadir Dagli.