Title :
Ultrahigh-speed traveling-wave electroabsorption modulator-design and analysis
Author :
Li, G.L. ; Sun, C.K. ; Pappert, S.A. ; Chen, W.X. ; Yu, P.K.L.
Author_Institution :
Dept. of Electr. & Comput. Eng., California Univ., San Diego, La Jolla, CA, USA
fDate :
7/1/1999 12:00:00 AM
Abstract :
Theoretical analysis and numerical calculations are presented for ultrahigh-speed (>50 GHz) traveling-wave electroabsorption modulators (TW-EAM´s), including effects of velocity mismatch, impedance mismatch, and microwave attenuation. A quasi-static equivalent circuit model is used to examine the TW-EAM microwave properties, including the effect of photocurrent. Due to the optical propagation loss of the waveguide, the TW-EAM waveguide length for maximum RF link gain is currently limited to 200-300 μm. The discussion indicates that the carrier transit time in the intrinsic layer may not severely limit the TW-EAM bandwidth. Three TW-EAM design approaches are discussed: low-impedance matching; reducing the waveguide capacitance; and distributing the modulation region
Keywords :
capacitance; electro-optical modulation; electroabsorption; equivalent circuits; frequency response; high-speed optical techniques; impedance matching; microwave photonics; optical communication equipment; optical losses; optical waveguide theory; photoconductivity; 200 to 300 micron; 50 GHz; carrier transit time; high-speed fibre optic links; impedance mismatch; intrinsic layer; low-impedance matching; maximum RF link gain; microwave attenuation; microwave properties; modulation region distribution; modulator bandwidth; optical propagation loss; photocurrent effect; quasi-static equivalent circuit model; traveling-wave electroabsorption modulator; ultrahigh-speed optical modulator; velocity mismatch; waveguide capacitance reduction; Bandwidth; Equivalent circuits; Impedance; Optical attenuators; Optical losses; Optical propagation; Optical waveguides; Photoconductivity; Propagation losses; Radio frequency;
Journal_Title :
Microwave Theory and Techniques, IEEE Transactions on
