ELECTRO-OPTIC MODULATOR HAVING HIGH EXTINCTION RATIO WHEN FUNCTIONING AS SWITCH

摘要

An electro-optic modulator includes a substrate, a Y-shaped waveguide, and electrodes. The waveguide is formed in the substrate with diverging and reconverging portions. The electrodes are formed in the substrate to sandwich the diverged portions of the waveguide and receive voltages which modulate each branch of the Y shaped waveguide such that power outputs of branches of the Y shape are precisely synchronized and an improved extinction ratio thus obtained.

主权项

1. An electro-optic modulator, comprising:
a substrate; a Y-shaped waveguide formed in the substrate and comprising a first Y-shaped section and a second Y-shaped section, the first Y-shaped section comprising a first branch and a second branch, the second Y-shaped section comprising a third branch and a fourth branch, the second and fourth branches being positioned at two opposite sides of the first and third branches; the substrate defining a first to third recesses, the first and third recesses being located at two opposite sides of the waveguide, the second recess being located between the first and second sections; a first modulating electrode fully filling the first recess; a first ground electrode positioned on the substrate and covering the second branch; a second modulating electrode positioned on the substrate and covering the first branch; a second ground electrode fully filling the second recess; a third modulating electrode positioned on the substrate and covering the third branch; a third ground electrode positioned on the substrate and covering the fourth branch; and a fourth modulating electrode fully filling the third recess.