Design of an integrated optical magic T for astronomy applications

A new integrated optical component is introduced that performs the function of the well-known microwave magic T, i.e., that produces the sum and the d ifference of the two input optical signals. Two structures are proposed and tested theoretically for this purpose. The first is based on the symmetric Y junction, and the second is based on interference phenomena in a multimo de waveguide. The theoretical design is tested with a beam-propagation meth od simulation, and good performance is obtained. The effects of the geometr ical design parameters on the structures' performance (bandwidth, cross tal k, and losses) are also investigated. (C) 2000 Optical Society of America O CIS code: 130.0130.