Broadband waveguide

A broadband waveguide configured to communicate a stress wave, comprising:

• a filament including a first end, a second end, and a length between the first and second ends, the filament formed of a material that is transmissive of stress waves, the first end of the filament configured to be coupled to a structure that generates a stress wave indicative of vibration or pressure at the structure such that the stress wave is introduced proximate the first end of the filament for passive broadband measurement of the vibration or pressure proximate an intermediate location of the filament between the first and second ends;
• and
• a cladding material at least partially engaging the filament, wherein the first end is hermetically sealed by the cladding material;
• wherein the filament further includes at least one reflection point configured to at least partially reflect the stress wave as a first reflection signal, and the second end reflects the stress wave as a second reflection signal, and the first reflection signal and the second reflection signal are out of phase.