Binary, fourier domain-synthesized gratings for multiple wavelength reflectors

A method of forming a binary Fourier-domain synthesized grating for generating a comb-like spectral reflection profile with adjustable comb line spacing, the method comprising:

• defining a target spectral reflection profile having a plurality of comb lines at desired wavelengths and amplitudes;
• selecting a uniform binary grating structure having a constant grating period corresponding to a Bragg wavelength of a specified comb line in the target spectral reflection profile and a length corresponding to a desired comb line spacing;
• determining a set of phase-shift locations within the uniform binary grating structure, wherein each phase-shift location introduces a quarter-wave shift in the grating periodicity, the phase-shift locations being selected to match the target spectral reflection profile;
• and
• incorporating the phase-shifts into the uniform binary grating structure at the selected phase-shift locations to thereby produce a grating superstructure;
• and
• arranging a plurality grating superstructures adjacent sequentially with respect to one another along the propagation direction of a light signal to form the binary Fourier-domain synthesized grating.