Patent ID: 7437392

Claim:
A method comprising transitioning a filter function of an optical delay line circuit filter from a start filter function to a target filter function, the step of transitioning comprises the steps of: (a) determining start filter coefficients defining a start filter function for said optical delay line circuit filter; (b) interpolating differences in values of said start filter function and said target filter function over the optical filter's spectral range to establish m−1 intermediate filter functions, where m is an integer and m≧=2; (c) determining best fit filter coefficients for a first intermediate filter function by performing an optimization process on filter coefficients using the start filter function coefficients to obtain the best fit solution to said first intermediate filter function; and (d) iteratively repeating step (c) to obtain best fit filter coefficients for any successive intermediate filter function utilizing in each iteration the best fit filter coefficients obtained from the preceding optimization step thereby resulting in a best fit solution to the filter coefficients of the target filter function of the optical filter.