The method using low Δ waveguides decreases the insertionloss of intersecting optical waveguides with grooves. Theoreticalanalysis by the beam propagation method or the plane wave expansionmethod shows the benefit of decreasing the insertion loss. Experimentalmeasurements on a trial matrix (21×21) showed that thetransmission loss greatly decreased with decreasing Δ. Thereflection loss was less sensitive to the positional deviation of thegroove than that of conventional Δ waveguides. The experimentalresults were used to calculate the total insertion loss. It decreasedfrom 5.72 dB to 3.28 dB when Δ decreased from 0.3% to 0.15% for amatrix scale of 50×50
展开▼
