An insertion tool for use in inserting a guide wire into a guide wire lumen of a catheter for use in a lumen of an endoscope. The permutations can include a reversed order of elements in the sequences, a reversed order of some or all of a set of address bits identifying locations of elements in the sequences, a concatenation of subsets of elements in odd and even locations of the sequences A and B, and combinations of these permutations. Semiconductor dice and semiconductor die assemblies are also disclosed. To suppress lateral color, specified conditions are satisfied for the Abbe numbers and the refractive indices of the positive refractive power lens elements that are included in the doublet components of the second lens group. Alternatively, the circulators may be incorporated into a bidirectional adddrop apparatus with bandpass filters coupled to two of the inputoutput ports.