  Silica-based anchored-membrane waveguides (T-Guides) are fabricated and
characterized from the visible to infrared with streak imaging. It is
numerically shown that the T-Guides can have wideband single-mode and
single-polarization (SMSP) properties over a span of 2.6 octaves.
Experimentally, a polarization-dependent loss difference of up to 90 dB/cm is
measured between orthogonal polarizations, and a record SMSP window of >1.27
octaves is observed, limited only by the available measurement equipment. These
measurements make a strong case for T-Guides for SMSP photonics, particularly
on high-index materials such as our previous demonstration on silicon.
