Net gain demonstration with glass hybrid optical amplifiers made by ion-exchange and wafer bonding

Abstract

Thanks to the maturing of rare-earth highly-doped materials, erbium-doped waveguide amplifiers (EDWAs) present a compact alternative to fiber amplifiers. While ion-exchanged EDWAs implemented on glass substrates provide the best passive characteristics, EDWAs based on thin films technologies offer a higher integration and amplification efficiencies. This paper proposes the realization of EDWAs in a new configuration which combines all these advantages. Indeed, this optical amplifier consists of an erbium/ytterbium-codoped glass guiding layer reported on an ion-exchanged strip formed on a passive glass substrate. The electromagnetic principle of operation of this hybrid structure is presented as well as simulations of its behaviour. Then, the realization and characterization of two different hybrid amplifiers is presented: the first one, based on a Tl + /K + ion-exchanged strip provides a high gain coefficient of 3.66 ± 0.25 dB/cm; whereas the second one, realized with a Ag + /Na + ion-exchanged strip, presents a good coupling efficiency with optical fibers, which allows the measurement of a 1 dB net gain.