Another problem is that known multi wavelength selective switches are relatively expensive to manufacture depending on said complicated structures or {HEAD ~ the number} of {TAIL ~ components} comprised 
of
Another problem is that known multi wavelength selective switches are relatively expensive to manufacture depending on said complicated structures or { HEAD ~ the number } of { TAIL ~ components } comprised
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH