Embodiments of the invention are directed a waveguide having a first waveguide segment that includes a set of first waveguide segment confinement parameters; a second waveguide segment having routing bends and a set of second waveguide segment confinement parameters; and a third waveguide segment having a set of third waveguide segment confinement parameters. The waveguide is configured to guide optical data according to an asymmetric optical-loss performance curve that is a plot of the sets of first, second, and third waveguide segment confinement parameters on a first axis; and a level of optical-loss performance that results from the sets of first, second, and third waveguide segment confinement parameters on a second axis. The sets of first, second, and third waveguide segment confinement parameters are configured to, collectively, maximize a predetermined worst-case optical-loss performance level of the asymmetric optical-loss performance curve within a range of waveguide fabrication tolerances.