We have designed and fabricated an InGaAsP-InP based spotsize converter (SS
C), which is compatible with the waveguide structure used in monolithic int
egrated ADM's and OXC's, In a first experiement, a total coupling loss to a
cleaved fiber of 4.2 dB for TE and 3.9 dB for TM was realized with a 1.5-m
m-long SSC. The l-dB alignment tolerances improved from 0.75 mu m to 2.4 an
d 2.2 mu m for the horizontal and vertical direction, respectively.