CURRENT Research interests

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·         Electro-Active Integrated Optical Waveguides


·         Impedance Spectroscopies and Electron Transfer Kinetics in Molecular Films


·         Micro-Fluidics for Simultaneous Optical and Electrical Flow-Cytometry


·         Super-Resolution and Electron State Depletion Imaging


·         Integrated Optical Devices and Bragg Gratings in Lithium Niobate


·         Ultra-Fast Laser Spectroscopies


·         Nano-Structured Surfaces for Efficient Solar Cells


·         Nano-Patterning with Holography, Reactive Plasma, and Ion Beam Etching


·         Plasmonic Devices



Lab Resources:


The Photonics Research Labs are housed in approximately 1,500 sq. ft. and are equipped with optical, photonic, and opto-electronic instrumentations and components.  In particular, we are well prepared for carrying out experiments in integrated optics, thin-films, biological and chemical assemblies, electrochemical analysis, guided-wave devices, and several optical spectroscopic techniques.  Furthermore, we largely benefit from dedicated equipment and custom-made hardware developed along the years for working with planar optical waveguides and fiber optics technologies, and integration of those technologies with spectroscopic tools for studies of molecular assemblies and surface-confined phenomena.

Major resources available in the Photonics Research Labs include:

  • 4 vibration-isolated optical tables (2 Newport smart tables, TMC, Melles Griot)
  • optical spectrum analyzer (Ando, OSA AQ-6315A)
  • CCD and ICCD cameras (Princeton, Pixis 400B and PI-MAX 3)
  • spectrographs (Acton/Princeton 2156 and 2358)
  • fast PMT detectors and high speed amplifiers (Hamamatsu R928, H5783-04, C5594)
  • oscilloscope (Agilent, DSO8104A Infiniium, 1 GHz, 4 channels)
  • gated integrators (Stanford Research Systems, SR 250, 280, 245)
  • fusion splicer (Ericson, FSU 995)
  • fiber cleaver (Fitel, S323)
  • femtosecond tunable laser (Coherent, Chameleon Ultra, 690-1020 nm, 2.5W, 140-fs pulse width)
  • He-Cd laser (Kimon, 325 and 442 nm, IK5651R-G)
  • 445-nm solid state laser (Coherent, OBIS LX, 75 mW)
  • 592-nm solid state laser (MPB, VFL-P 1500-592, 1.5 W)
  • tunable nanosecond pulsed laser (Continuum, Panther EX OPO with doubler and Surelite SL I-20)
  • super-continuum laser (Fianium, SC-400-4) with acousto-optical tunable filter (400-650 nm)
  • argon-ion laser (Melles Griot, 35-LAP-321-208) multiple-lines He-Ne laser (Thorlabs, HTPS)
  • single-line He-Ne laser (Thorlabs, HRP 120)
  • deuterium/tungsten-halogen fiber-coupled light source (Hamamatsu L10290)
  • 405-nm semiconductor laser (Nichia, 120 mW, single-mode) and current/temperature controllers
  • potentiostat (Ch Instruments, CHI660D)
  • optical coater
  • lapping and polishing machine (Lapmaster, model 12)
  • high resolution metallurgical microscope (VWR, VistaVision, T-RTP 43300-548)
  • UV-Vis spectrophotometers (Varian Cary 300, SI-Photonics 430)
  • prism coupler and attenuation measurement (Metricon, 2010)
  • power-meters (Newport, 1830 C and 1930 C)
  • power/energy meter (Newport, 842 PE)
  • fast and sensitive detector heads (Newport, 818 UV/CM; NewFocus, 2051)
  • lock-in amplifier (Stanford Research Systems, SR 830)
  • current amplifier (Stanford Research Systems, SR 570)
  • optical chopper (Stanford Research Systems, SRS 540)
  • high precision 5X translation stages (Newport, Ultra-Align 561 and matching accessories)
  • interferometric instrumentation for flatness measurements
  • 0.001º-precision rotation stage (Danaher)
  • 3 cabinets with fume hood ventilation for chemical preparation
  • wet-bench for chemical preparation
  • 18.2 MΩ cm de-ionized water (Millipore, Direct Q-3 with UV pump)
  • ultrasonic cleaner (Branson, 2510)
  • pH meter (Symphony, SB 70P)
  • vacuum oven (VWR, Squaroid)
  • analytical balance (Metler Toledo, AB 104-S/FACT, 0.1 mg)
  • LabView and driver for computer interface
  • spin processor (Laurell, WS-650Mz-23NPP)
  • several personal computers
  • 9 office desks for postdocs, graduate and undergraduate students


 selected publications:

·         Courtney L. Byard, Han Xue, and Sergio B. Mendes, “Angle-Multiplexed Waveguide Resonance of High Sensitivity and Its Application to Nanosecond Dynamics of Molecular Assemblies”, Analytical Chemistry (2012) 88, 9762. (pdf)

·         Rodrigo S. Wiederkehr, Geoffrey C. Hoops, and Sergio B. Mendes, “Effects of sodium chloride on the properties of chlorophyll a submonolayer adsorbed onto hydrophobic and hydrophilic surfaces using broadband spectroscopy with single-mode integrated optical waveguides”, Optical Eng (2011), 50, 071109. (pdf)

·         Marcelo B. Pereira, Jill S. Craven, and Sergio B. Mendes, “Solid Immersion Lens at the Aplanatic Condition for Enhancing the Spectral Bandwidth of a Waveguide Grating Coupler”, Optical Eng (2010), 49, 124601, Optical Eng (2010), 49, 124601. (pdf)

·         Mustafa M. Aslan, Nathan A. Webster, Courtney L. Byard, Marcelo B. Pereira, Colin M. Hayes, Rodrigo S. Wiederkehr, and Sergio B. Mendes, “Low-Loss Optical Waveguides for the Near Ultra-Violet and Visible Spectral Regions with Al2O3 Thin Films from Atomic Layer Deposition”, Thin Solid Films (2010), 518, 4935-4940. (pdf)

·         S.B. Mendes, S.S. Saavedra, and N.R. Armstrong, “Broadband Spectroelectrochemical Interrogation of Molecular Thin Films by Single-Mode Electro-Active Integrated Optical Waveguides”, invited book chapter in "Optical Guided-Wave Chemical and Biosensors," Editors: Zourob, M. and Lakhtakia, A.; Springer-Verlag book series on Chemical Sensors and Biosensors (2010), ISBN 978-3-540-88241-1, 101-129. (pdf)

·         Rodrigo S. Wiederkehr, Geoffrey C. Hoops, Mustafa M. Aslan, Courtney L. Byard and Sergio B. Mendes, “Investigations of the Q and CT Bands of Cytochrome c Adsorbed onto Alumina Surfaces Using Broadband Spectroscopy with Single-Mode Integrated Optical Waveguides”, J. Phys. Chem. C (2009), 113, 8306-8312. (pdf)

·         Beam, B. M.; Armstrong, N. R.; and Mendes, S. B. “An Electroactive Fiber Optic Chip for Spectroelectrochemical Characterization of Ultra-Thin Redox Active Films”. Analyst (2009) 134, 454-459, featured article for the issue cover. (pdf)

·         Araci, I. E.; Mendes, S. B.; Yurt, N.; Honkanen, S.; Peyghambarian, N.  “Highly Sensitive Spectroscopic Detection of Heme-Protein Submonolayer Films by Channel Integrated Optical Waveguide”.  Optics Express (2007) 15(9), 5595-5603. (pdf)

·         Runge, A. F; Saavedra, S. S.; Mendes, S. B.  “Combination of Polarized TIRF and ATR Spectroscopies for Determination of the Second and Fourth Order Parameters of Molecular Orientation in Thin Films and Construction of an Orientation Distribution based on the Maximum Entropy Method”.  Journal of Physical Chemistry B (2006) 110(13), 6721-6731. (pdf)

·         Runge, A. F.; Rasmussen, N. C.; Saavedra, S. S.; Mendes, S. B.  “Determination of Anisotropic Optical Constants and Surface Coverage of Molecular Films Using Polarized Visible ATR Spectroscopy”.  Application to Adsorbed Cytochrome c Films.  Journal of Physical Chemistry B (2005) 109(1), 424-431. (pdf)

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