Light waveguiding within phosphate glasses upon post-melting encapsulation of glass microwires

Glass waveguides are the fundamental component of advanced photonic circuits and play a pivotal role in diverse applications, including quantum information processing, light generation, imaging, data storage, and sensing platforms. Until today, the development of glass-based optical waveguides relies mainly on demanding chemical processes and on the utilization of ultrafast laser equipment. Herein, we present recent findings on an advanced, feasible, low-temperature, post-melting encapsulation synthesis method for the fabrication of glass waveguides. At first, silver iodide phosphate glass microwires (MWs) are drawn from splat-quenched glasses. Following this, the so-formed MWs are incorporated in a controlled manner within transparent silver phosphate glass matrices. The selection of glass compositions ensures that the refractive index of the host phosphate glass is lower than that of the embedded MWs. This facilitates the propagation of light inside the encapsulated higher refractive index MWs, leading to the facile development of waveguides. Employing this innovative approach, we have successfully engineered waveguide devices incorporating either one or two MWs. Remarkably, the double MW devices are capable of transmitting light of different colors and in multipath direction, rendering the developed waveguides outstanding candidates for extending the functionalities of diverse photonic and optoelectronic circuits, as well as in smart glass technologies.