A new type of cutoff light modulator, which consists of a single-mode channel waveguide and strip electrodes placed asymmetrically on either side of the guide, is proposed. When a voltage is applied to the electrodes, this device exhibits an asymmetric refractive-index profile along a direction parallel to the crystal surface through the electro-optic effect. This produces a strong condition for cutoff of the fundamental mode of the guide. An ultrahigh extinction ratio of greater than 56 dB has been achieved by using a Ti-indiffused Y-cut LiNbO3 cutoff modulator with a 165-V drive at a wavelength of 0.6328 μm.
© 1986 Optical Society of America
Original Manuscript: April 17, 1986
Manuscript Accepted: September 24, 1986
Published: December 1, 1986
Kuniharu Takizawa, "Electro-optic cutoff modulator using a Ti-indiffused LiNbO3 channel waveguide with asymmetric strip electrodes," Opt. Lett. 11, 818-820 (1986)