We present our investigation of a variable bandwidth, ultrafast magneto-optic waveguide modulator employing the ferromagnetic resonant precession of the magnetization in a Bizmuth-substituted YIG film. Ultrafast magnetic field pulses, produced by current pulses propagated through a high-speed transmission line, are used to modulate the optical beam in the film. Such a device is capable of multi- gigahertz bandwidth and potential integration into current IC technology. Single frequency modulation of an 800 nm optical carrier is measured at bandwidths tuned between 4.6 and 11.7 GHz. The bandwidth is tuned by means of an externally applied DC magnetic field. It is found that the mode conversion efficiency of a waveguide type of device is limited by the linear birefringence of the thin Bi-YIG film. Birefringence-compensating schemes are discussed to optimize the mode conversion.

Date Published: 12 November 1999
PDF: 8 pages
Proc. SPIE 3795, Terahertz and Gigahertz Photonics, (12 November 1999); doi: 10.1117/12.370158

Published in SPIE Proceedings Vol. 3795:
Terahertz and Gigahertz Photonics
R. Jennifer Hwu; Ke Wu, Editor(s)