Design and fabrication of a directional coupler by photolithography technique

In this article design and fabrication of the directional coupler are investigated. A directional coupler has been made of two waveguides. It has been constructed by laser beam direct write lithography technique. We used optical polymer for fabricating a directional coupler due to it`s very low loss at 1550 nm and 1300 nm wavelengths. This coupler is characterized for a broadband ELED at 1550 nm. Moreover, we used a tapered fiber to couple light into the bus waveguide. Then it has been received from the output port of the waveguide using another tapered fiber and has been monitored by optical spectrum analyzer