  We propose and theoretically investigate integrated photonic filters based on
coupled Sagnac loop reflectors (SLRs) formed by a self-coupled wire waveguide.
By tailoring coherent mode interference in the device, three different filter
functions are achieved, including Fano-like resonances, wavelength
interleaving, and varied resonance mode splitting. For each function, the
impact of device structural parameters is analyzed to facilitate optimized
performance. Our results theoretically verify the proposed device as a compact
multi-functional integrated photonic filter for flexible spectral shaping.
