Abstract
Optical splitters and combiners which can provide precise splitting with low loss, high thermal stability, large optical bandwidth, high compactness and insensitivity to fabrication tolerances are essential components for high performance MZI based optical modulators. In this paper we theoretically and experimentally investigate the MMI and the reduction in optical loss achievable through the use of linear tapers at the input and output ports. Our data shows that losses can be reduced to below 1dB/MMI without affecting the static extinction when employed in MZIs.