Study of a pump/signal multiplexer based on a segmented asymmetric Y junction by silver/sodium ion exchange on glass

Broadband wavelength (de)multiplexers play a key role in different fields of integrated optics. In particular, the development of Erbium Doped Waveguide Amplifiers (EDWA) requires efficient integrated pump/signal multiplexers. In this article, the design and the realization of a 980 nm/1550 nm wavelength multiplexer based on a segmented asymmetric Y junction made by silver/sodium ion exchange on glass is discussed. We first present the behavior of an asymmetric Y junction, in order to describe its use as a wavelength (de)multiplexer. Then, the index averaging principle of a segmented waveguide is detailed, as well as its application in the design of one of the asymmetric Y junction branches. The design of a segmented asymmetric Y junction is then described, as well as its BPM simulations results. They show isolation of 33 dB at 980 nm and 25.6 dB at 1550 nm with excess losses of 2.6 dB at 980 nm and 1.3 dB at 1550 nm. In a second time, we present the realization of this component using a Silver/Sodium ion-exchange on glass. For λ = 980 nm, the isolation measured is (31 ± 1) dB, and in the third communication window, the isolation increases from (11.5±0.25) dB at λ = 1500 nm to (15.5±0.25) dB at λ = 1600 nm. The broadband operation is only limited by the modal characteristics of the waveguides composing the junction and ranges from 1500 nm to 1650 nm. Total insertion losses measured at 980nm are (2.63±0.1) dB. Around 1550 nm, losses vary from (3.6 ± 0.1) dB at the 1500 nm wavelength to (4.6 ± 0.1) dB at 1600 nm.