KLu(WO<sub>4</sub>)<sub>2</sub>/SiO<sub>2</sub> Tapered Waveguide Platform for Sensing Applications
Marc Medina,
Christian E. Rüter,
Maria Cinta Pujol,
Detlef Kip,
Jaume Masons,
Airán Ródenas,
Magdalena Aguiló,
Francisco Díaz
Affiliations
Marc Medina
Física i Cristallografia de Materials i Nanomaterials (FiCMA-FiCNA-EMaS), Departament de Química Física i Inorganica (DQFI), Universitat Rovira i Virgili (URV), Campus Sescelades, C/Marcellí Domingo 1, E-43007 Tarragona, Spain
Christian E. Rüter
Faculty of Electrical Engineering, Helmut Schmidt University, 22043 Hamburg, Germany
Maria Cinta Pujol
Física i Cristallografia de Materials i Nanomaterials (FiCMA-FiCNA-EMaS), Departament de Química Física i Inorganica (DQFI), Universitat Rovira i Virgili (URV), Campus Sescelades, C/Marcellí Domingo 1, E-43007 Tarragona, Spain
Detlef Kip
Faculty of Electrical Engineering, Helmut Schmidt University, 22043 Hamburg, Germany
Jaume Masons
Física i Cristallografia de Materials i Nanomaterials (FiCMA-FiCNA-EMaS), Departament de Química Física i Inorganica (DQFI), Universitat Rovira i Virgili (URV), Campus Sescelades, C/Marcellí Domingo 1, E-43007 Tarragona, Spain
Airán Ródenas
Departamento de Física, Instituto de Estudios Avanzados (IUdEA), Universidad de la Laguna (ULL), E-38200 San Cristóbal de La Laguna, Spain
Magdalena Aguiló
Física i Cristallografia de Materials i Nanomaterials (FiCMA-FiCNA-EMaS), Departament de Química Física i Inorganica (DQFI), Universitat Rovira i Virgili (URV), Campus Sescelades, C/Marcellí Domingo 1, E-43007 Tarragona, Spain
Francisco Díaz
Física i Cristallografia de Materials i Nanomaterials (FiCMA-FiCNA-EMaS), Departament de Química Física i Inorganica (DQFI), Universitat Rovira i Virgili (URV), Campus Sescelades, C/Marcellí Domingo 1, E-43007 Tarragona, Spain
This paper provides a generic way to fabricate a high-index contrast tapered waveguide platform based on dielectric crystal bonded on glass for sensing applications. As a specific example, KLu(WO4)2 crystal on a glass platform is made by means of a three-technique combination. The methodology used is on-chip bonding, taper cutting with an ultra-precise dicing saw machine and inductively coupled plasma-reactive ion etching (ICP-RIE) as a post-processing step. The high quality tapered waveguides obtained show low surface roughness (25 nm at the top of the taper region), exhibiting propagation losses estimated to be about 3 dB/cm at 3.5 μm wavelength. A proof-of-concept with crystal-on-glass tapered waveguides was realized and used for chemical sensing.
