The present invention involves the use of coupling fixtures that permit optical elements to be aligned with planar waveguides of planar lightwave circuits. In particular, alignment of the coupling fixtures typically does not require powering of the optical element yet provides a degree of alignment that is comparable to that obtained by active alignment techniques. The alignment process is accompanied by an assembly process that may be performed at relatively high temperatures. This typically makes it possible to use solder for attaching the optical element to the planar lightwave circuit while retaining alignment accuracy. This is advantageous since soldering typically is the preferred choice for assembling components, such as single-mode devices, that require a relatively high degree of alignment precision together with good mechanical rigidity.