High-bandwidth velocity-matched optical directional coupler modulator in A1GaAs/GaAs

M. Nisa Khan, Anand Gopinath, Julian P.G. Bristo

Research output: Contribution to journalConference articlepeer-review


We report a design of a very high frequency A1GaAs/GaAs optical modulator using a dielectric loading velocity matching technique. The optical modulator is a directional coupler which is covered with a thin coating of Ta205 to match the velocities of the lightwave and the if modulating signal to within 2%. The optical and rf characteristics of the modulator are analyzed using the effective index and finite difference methods. The small signal 3 dB bandwidth for the modulator is predicted to exceed 45 GHz and 100 GHz for biasing at the null point and in the linear region respectively, with a maximum modulation voltage of 5V at 830nm wavelength.

Original languageEnglish (US)
Pages (from-to)260-263
Number of pages4
JournalProceedings of SPIE - The International Society for Optical Engineering
StatePublished - 1991
EventIntegrated Optoelectronics for Communication and Processing 1991 - Boston, United States
Duration: Sep 1 1991Sep 7 1991

Bibliographical note

Publisher Copyright:
© 1991 SPIE. All rights reserved.


Dive into the research topics of 'High-bandwidth velocity-matched optical directional coupler modulator in A1GaAs/GaAs'. Together they form a unique fingerprint.

Cite this