Strip-Loaded Sol-Gel Waveguides: Design and Fabrication

Abstract

Sol-gel is one of the most attractive techniques for production of silica-on-silicon integrated optical devices. In fact, it combines low cost with flexibility and ease of doping; thus, nonlinear and active compounds can be effectively included in the silica matrix. Here, the feasibility of applying the sol-gel technique to the realization of an erbium-doped optical amplifier is reported on, operating in the third telecommunication window. In particular, the development of an optimum strategy for the design and fabrication of a guiding structure in the strip-loaded configuration is described. Design optimization results, as well as fabrication results and measured characteristics, are described and discussed.

X-ray photoelectron spectroscopy of erbium-activated-silica–hafnia waveguides

“…Several techniques have been investigated for the productions of silica based integrated planar waveguides. In particular sol-gel is one of the most promising techniques because of its relatively low cost and high versatility [2,3]. Among the several silica-based glasses it was demonstrated that the SiO 2 -HfO 2 binary system presents valuable prospects for successful photonic applications [3][4][5].…”

Sol–gel-derived Er-activated SiO2–HfO2 planar waveguides for 1.5μm application

“…Nowadays, the sol-gel process has emerged as an effective route for the fabrication of SiO 2 -based planar waveguides with valuable prospects for EDWAs fabrication [7][8][9][10]. In previous papers we presented some results about a set of 70SiO 2 -30HfO 2 planar waveguides, doped with different erbium concentration ranging between 0.01 and 4 mol%, prepared by the sol-gel technique with dip-coating processing.…”

Sol-gel Er-doped SiO2–HfO2 planar waveguides: A viable system for 1.5 μm application

“…6,7 Among the silica-based systems, binary SiO 2 -TiO 2 has been widely used to produce Er-activated planar waveguides by sol-gel route. 1,2,8,9 However, in the silica-titania system, there is a tendency for separation between SiO 2 -rich and TiO 2 -rich phases. Undesirable phase precipitation can take place as a consequence of the thermal treatment, necessary to achieve full densification of the film, or during the reflow process.…”

“…[1][2][3] In particular, SiO 2 based planar waveguides produced by sol-gel route, could be promising materials for Erdoped waveguide amplifiers ͑EDWA͒ to be used in metropolitan area networks. [1][2][3][4][5] The key requirements for developing EDWAs by the sol-gel route are: ͑i͒ refractive index and thickness of the film have to be tailored, in order to satisfy both single-mode condition at 1.5 m and efficient coupling to fibers; ͑ii͒ the structural and optical homogeneity have to be optimized, in order to reduce losses and rare-earth clustering; 1,5 and ͑iii͒ the OH groups must be effectively removed, because the 4 I 13/2 luminescence of OH Ϫ -coordinated Er 3ϩ ions is completely quenched by two phonon-OH mechanism. 6,7 Among the silica-based systems, binary SiO 2 -TiO 2 has been widely used to produce Er-activated planar waveguides by sol-gel route.…”