Optimum bandpass optical filter synthesis using periodic corrugated waveguides with π/2 phase shifts

A graphical method is proposed for the synthesis of optical bandpass filters, using /spl pi//2-phase shift sections. Bandpass filters with the desired characteristics, such as central wavelength, bandwidth, ripple factor, selectivity, minimum attenuation etc., can be synthesized by proper choice of corrugation pitch, coupling coefficient, filter length, and the location of /spl pi//2-phase shift sections. This method is relatively simple as compared to the previous works. Besides, it allows to optimize certain criteria.>