Patent ID: 7693371

Claim:
A chirp optical waveguide comprising a substrate of ferroelectric material having a chirp grating and a waveguide part, said chirp grating including a plurality of grating segments arranged serially in a light propagation direction, the number of said grating segments being larger than two, said chirp grating having a normalized grating period Λx/Λ 0 that increases exponentially in each of said grating segments as a wave propagation distance increases and decreases stepwise from each of said grating segments to a following one of said grating segments, where Λ 0 is an initial grating period at the wave propagation distance of zero, and Λx is a grating period at the wave propagation distance of x, wherein each of said grating segments has an upstream boundary, and a downstream boundary, said downstream boundary of each of said grating segments being at the same wave propagation distance as said upstream boundary of a following one of said grating segments, said normalized grating period increasing exponentially from said upstream boundary to said downstream boundary in each of said grating segments.