The 4 x 4, 1 x 2, and 1 x 4 semiconductor optic-switch modules for 1550 nm
optical communication systems were fabricated by using the laser welding te
chnique based on the 30-pin butterfly package. For better coupling efficien
cy between a switch chip and an optical fiber, tapered fibers of 10-15 mum
lens radius were used to provide the coupling efficiency up to 60%. The len
s to lens distance of the assembled tapered fiber array was controlled with
in +/-1.0 mum. A laser hammering technique was introduced to adjust the rad
ial shift, which was critical to obtain comparable optical coupling efficie
ncies from all the channels at the same time. The fabricated optical switch
modules showed good thermal stability, with less than 5% degradation after
a 200 thermal cycling. The transmission characteristics of the 4 x 4 snitc
h module showed good sensitivities, providing error free transmissions belo
w -30 dBm for all the switching paths, The dynamic ranges for the 4 x 4 and
1 x 2 snitch modules were about 8 dB for a 3 dB penalty and about 17 dB fo
r a 2 dB penalty, respectively.