Modeling and realization of a new broadband wavelength multiplexer demultiplexer

With the increase of optical communications bit rate, the interest for broad-band integrated optic Wavelength Demultiplexers Multiplexers (WDM) devices is growing. Their applications include, for example, the fiber communications on a single fiber by adding the transmission capacity of both optical telecommunication windows at the wavelengths 1.31 mum and 1.55 mum. They also achieve to combine pump and signal wavelengths in rare earth doped integrated optical amplifiers and lasers. A promising technology to realize those devices is ion-exchange on glass which allows the integration of different functions in a glass substrate with efficient results and an excellent compatibility with fiber systems. In this paper, an original design of a broad-band duplexer is presented. The principle of the device is first explained. Then numerical and experimental results confirming good performances are shown. Instead of using phase-matched coupling as it is usually done, we propose a structure based on distributed coupling. This particularity entails a low sensitivity to technological parameters and a broad-band behavior. As a validation, a test device has been realized by ion-exchange on glass.