Optimization of thermally tunable grating filters with air trench and beam-pillar structures

Abstract

Thermally tunable grating filters are promising filtering devices with low power consumption and low cost. Based on our previous work, we optimize the tuning performance and mechanical stability of a thermally tunable grating filter with air trench and beam-pillar structures. With finite element method, the Joule heat production, thermal transfer, stress, deformation and temperature response speed are studied. By theoretical analysis, two formulas for predicting the response speed are derived. Simulation results show that the two optimized cases of different structure parameters have good mechanical stability under the temperature rise of 70 °C. Furthermore, using silicon nitride as cladding material, the tuning efficiency can be improved better than 0.5 nm/mW and the response time can be reduced smaller than 50μs.