  We present a novel chiral sensing platform that combines a one-dimensional
photonic crystal design with a birefringent surface defect. The platform
sustains simultaneous transverse electric and transverse magnetic surface
modes, which are exploited to generate chiral surface waves. The present design
provides homogeneous and superchiral fields of both handednesses over
arbitrarily large areas in a wide spectral range, resulting in the enhancement
of the circular dichroism signal by two orders of magnitude, thus paving the
road toward the successful combination of surface-enhanced spectroscopies and
electromagnetic superchirality.
