Chromatic characterization of directional couplers fabricated by Na+/K+ ion-exchange in glass for the short wavelength band 700–900 nm

A chromatic characterization is presented for directional couplers fabricated by Na/K ion-exchange in glass to work in the short wavelength band 700–900 nm. This band is particularly important for free-space optical communications because presents a good atmospheric transmission and allows the use o...

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Detalles Bibliográficos
Autores: Varela Carballo, Javier, Prieto Blanco, Xesús, Montero Orille, Carlos, Liñares Beiras, Jesús
Tipo de recurso: artículo
Fecha de publicación:2025
País:España
Institución:Universidad de Santiago de Compostela (USC)
Repositorio:Minerva. Repositorio Institucional de la Universidad de Santiago de Compostela
Idioma:inglés
OAI Identifier:oai:minerva.usc.gal:10347/44048
Acceso en línea:https://hdl.handle.net/10347/44048
Access Level:acceso abierto
Palabra clave:Ion-exchanged glass optical waveguides
Chromatic properties of optical waveguides
Integrated directional couplers
Descripción
Sumario:A chromatic characterization is presented for directional couplers fabricated by Na/K ion-exchange in glass to work in the short wavelength band 700–900 nm. This band is particularly important for free-space optical communications because presents a good atmospheric transmission and allows the use of silicon commercial detectors. Moreover, directional couplers are the fundamental bricks to develop different integrated devices to implement classical and quantum specific functions as, for example, in chip-based free-space optical communications. Accordingly, empiric curves for directional modal coupling chromatic dispersion are obtained for both abrupt (without approach curves) and gradual directional couplers in this short wavelength band. Interestingly, we observe an anomalous directional modal coupling dispersion related to a lower dispersion of the surface index with respect to the substrate in ion-exchanged Na/K waveguides. The results obtained allow the determination of the fabrication process parameters of integrated devices based on directional couplers in this short wavelength band, which is illustrated with a particular device to generate quantum states.