device 601 or on chassis 500 the alignment between devices 501 and 601 may be within conventional mechanical tolerances such as 10 microns the most important aspect of the alignment between devices 501 and 601 is the parallelism of the planes of the respective substrates 200 of devices 501 and 601 about the axes of the waveguides of respective optical devices 202 as seen in fig7 b a lens module 608 preferably comprising a lens 609 fixedly mounted onto a mounting substrate 610 is brought into proximity with substrate 200 of device 601 and active integrated optics waveguide device 202 of device 601 as by a vacuum engagement assembly 611 connected to a suitable positioner not shown such as melles griot nanoblock as seen in fig7 c the lens module 608 is precisely positioned with respect to the active integrated optics waveguide device 202 of device 601 with six degrees of freedom so as to achieve a high degree of accuracy in order to realize optimal optical coupling efficiency between the fibers of fiber bundle 502 and the waveguides in device 202 of device 601 this degree of accuracy is greater than that required in the previously described alignment steps illustrated in fig1 a 1i and preferably reaches one tenth of a micron precise mounting of the lens module 608 with respect to the active integrated optics waveguide device 202 of device 601 as described hereinabove with.