Double-chirped waveguide grating router with angled ports

Abstract

An improved waveguide grating router occupies less physical volume than prior-art designs, and provides a spectral response with substantially one dominant passband, by providing nonlinearly-changing angles between the central axis of a waveguide coupler and each of a plurality of waveguide arms, and by providing waveguide arms having nonlinearly-changing lengths. The router includes a first waveguide coupler, a second waveguide coupler, and a plurality of M waveguides coupled between the first and second waveguide couplers. Each waveguide m has a length L(m) and forms an angle .alpha.(m) with respect to the central axis of the second waveguide coupler. The difference in angle (.DELTA..alpha.) between any two adjacent waveguides, m and (m-1) is equal to an arbitrary constant j plus (B*m) for each of the waveguides. The difference in length (.DELTA.L) between any two adjacent waveguides, m and (m-1), is equal to an arbitrary constant k plus (A*m) for each of the waveguides. Values of A and B are selected such that, for each of a plurality of waveguides, the transmissivity of a dominant passband selected from a plurality of passbands is enhanced.

Dependencies are inferred from the claim text.