The Research Of Analysis Model For Effect Of Thermal Stress On Optical Filter Performance

Photonic devices are the core and foundation for modern optical communication system and networks. Reliability of photonic devices is very important for practicality of the devices in field use, which has drawn more and more attentions. Thus research for reliability of photonic devices is of great help, both theoretically and practically, for technology development of photonic devices in China. Optical filter is one kind of important wavelength selection device in optical communication systems. Thermal stress is thought to be a key factor leading to degradations and failures of optical filters. Thermal stresses from working environments not only can lead to acceleration of the device aging, but also can affect the device performance directly. This paper mainly studies the effects of thermal stresses on optical performance of optical filters.With theories for thermal stress effect analysis and optical performance analysis summarized at the begining, a thermal effect analysis scheme is then proposed for photonic devices in this thesis. The main idear of the scheme is to synthetically analyze the heat-induced temperature distribution, according refractive index change, and optical performance of optical filters, by which effects of thermal stresses on the output performance of optical filters can be worked out. And a thermal effect analysis model has been established for optical filters based on commercial softwares and thermo-optical theory, where Ansys Multiphysics is used for stable state thermal distribution calculation; RSoft Photonices utilized for the simulation of optical filter performance; and thermo-optical theory used to establish relationships between the outcomes from these simulations. In this way, effects of thermal stress on optical filter performance can be analized.By applying the proposed model to an optical filter chip design scheme, internal temperature distribution of the filter has been analyzed for all kinds of thermal conditions, where the chip is assumed to have different core position on y-axis, different thermal conductivity, and under different environmental temperatures; and changes of the filter spectral characteristics and insertion loss parameters with respect to environmental thermal stress are analyzed as well. Furture more, the relationship between the thermal stress and output performance of this optical filter has been built up, with effect of heat upon optical filter’s output performance obtained. Finally, based on the simulation results, suggestions were presented for decreasing of thermal stress effects on optical filters.