Er³⁺-doped tellurite glass waveguides produced by Fiber on Glass (FOG) method

In this work we used a Thermal Mechanic Analysis equipment to produce the channel FOG waveguides by pressing an Er³⁺ doped tellurite glass optical fiber against one Er³⁺ ion doped tellurite glass substrate kept under T_c ±30 °C (T_c = soft point). The luminescence and waveguide refractive index were measured. Scanning electron microscopy was used to observe the obtained structure. The objective is to produce a new concept in components of integrated optical circuits. Then this work report the production of Er³⁺-doped tellurite glass channel waveguides using the novel concept of Benson et al^[1] of fiber on glass (FOG). To succeed with this technique it is important to correlate the main thermo-physical characteristics of the substrate and the fiber, which are the transition temperature T_g, the temperature of the onset of crystallization T_x, the maximum crystallization temperature T _c and the thermal expansion coefficient. The T_g, Tx and Tc values were determined by Differential Thermal Analysis (DTA), while the thermal expansion coefficient was determined by Thermal Mechanical Analysis (TMA). For the FOG purpose the thermal stability range, T_x - T _g, is an important temperature region which defines if the glass will have enough viscosity to shape in the FOG concept.