Title : Improving thermo-optic phase shifter technology using silicon strip waveguide with TiN heaters
Abstract:
The application of thermo-optic phase shifters (TOPSs) using silicon-on-insulator (SOI) technology provides an appealing solution across various fields such as sensors, high-speed communications, filters, and broadband electro-optic modulators. In these contexts, TOPSs play a crucial role in modulating light through either intensity or phase adjustment. Typically, TOPSs are fabricated monolithically, utilizing silicon (Si) as the waveguide (wg), alongside other dielectric materials like silica (SiO2) as the cladding, and various metals/doped semiconductors for the heating elements. To address the imbalance issue in Mach–Zehnder modulator (MZM) fabrication, a commercial thermo-optic phase shifter (TOPS) emerges as an effective solution. This device efficiently converts electrical power into thermal energy, thereby modifying the effective refractive index within the waveguide and optimizing the MZM transfer function for improved linearity. While conventional methods rely on a single heater, resulting in higher electrical power requirements and increased system costs, our innovative approach introduces an optimized double titanium nitride heater configuration. Implemented under forward biasing at a 1550 nm wavelength using standard silicon-on-insulator technology, this pioneering design undergoes rigorous numerical analysis. By investigating critical geometric parameters, silicon layer thermal distribution, thermal interference, and laser wavelength variations, our findings demonstrate that the optimal TOPS design operates with only 19.1 mW electrical power to achieve a π-phase shift. Importantly, it exhibits minimal thermal interference (0.404) and negligible optical losses over a 1 mm length. This breakthrough design not only resolves the imbalance issue in MZMs but also substantially reduces electrical power consumption, making it a cost-effective solution. This innovative device holds promise for enhancing the performance of transmitter systems in data centers and long-range optical communication applications. By combining low power consumption with minimal losses, it represents a significant advancement in improving the efficiency and cost-effectiveness of optical communication systems.
Audience Takeaway Notes:
- It will help to understand how to design thermo-optic phase shifter devices
- It will help them to design silicon photonic chips.
- Yes, it can be used to improve the power losses which is a cause of the need of using a larger RF line.
- Yes, it will improve the accuracy of phase shifter design.
