Use of MgO indiffusion to improve the optical performance of Ti indiffused LiNbO3 waveguide modulators

D.R. Gibson, C. Sharp

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Citation (Scopus)


The use of subsequent MgO indiffusion to bury Ti indiffused waveguides in LiNbO3 is shown to reduce the surface scatter contribution to waveguide propagation loss. Assessment of waveguide propagation loss for non-buried and buried waveguides at wavelengths 0.85μm, 1.06μm, 1.32μm and 1.52μm show a λ-2 dependence for non-buried waveguides, indicating a surface scatter mechanism. Buried waveguide propagation loss exhibits no such dependence on wavelength, with a propagation loss of ~0.25dB/cm over the wavelength range. Reduced excess loss of buried Y-junction waveguide structures, in Mach Zehnder intensity modulators, is demonstrated. This improvement is ascribed to increased light confinement and reduced scatter in the vicinity of the bifurcation region. Active performance of phase and intensity modulators, with non-buried and buried waveguides, indicate no significant change in required drive voltage. This is due to a choice of MgO conditions which lead to sufficient waveguide burial to reduce propagation loss, but to little change in Ti diffusion depth and hence optical/electrical field overlap characteristic. © 1990 SPIE.
Original languageEnglish
Title of host publicationIntegrated Optics and Optoelectronics
PublisherSociety of Photo-Optical Instrumentation Engineers
Number of pages8
Publication statusPublished - 5 Jan 1990
EventOE/Fibers '89 - Boston, United States
Duration: 5 Sep 19897 Sep 1989

Publication series

NameProceedings of SPIE - International Society for Optical Engineering
PublisherSociety of Photo-Optical Instrumentation Engineers


ConferenceOE/Fibers '89
Country/TerritoryUnited States


  • Light modulators
  • Magnesia
  • Surface measurement
  • Intensity modulators
  • Light confinements
  • Mach-Zehnder intensity modulators
  • Optical performance
  • Overlap characteristics
  • Waveguide modulator
  • Waveguide propagation
  • Waveguide structure
  • Waveguides


Dive into the research topics of 'Use of MgO indiffusion to improve the optical performance of Ti indiffused LiNbO3 waveguide modulators'. Together they form a unique fingerprint.

Cite this