Thermally Tunable Low Loss Broadband Waveguides and Related Systems and Methods

A method of refurbishing an optical system, the method comprising replacing a reference arm of the optical system with a waveguide for electromagnetic waves, wherein the waveguide comprises:

• an optical path written into a pattern, the pattern including a plurality of segments of the optical path and a plurality of stitch boundaries therein,
• wherein at each of the stitch boundaries at least one of the segments of the optical path is stitched together with another of the segments of the optical path, and,
• at least some of the stitch boundaries, the optical path defines an outward taper having a maximum width greater than a width of the optical path at portions of the associated segments remote from the at least one of the stitch boundaries.