A system and associated methods are disclosed for profiling the execution of program code by a processor. The molten material passageway comprises an interior surface and a protective layer is adjacent at least a portion of the interior surface of the passageway. The coupler may include a conductive strip, a terminating load, a dielectric material, a first ground plane, and a second ground plane. Therefore, read-only information recording medium of ultra-high memory capacity, equivalent to the memory capacity achievable by volume holography, can be produced by using a low-cost planar holographic technique.