Hybrid SIN-SOI Bragg Filter in Presence of Stress-Optic Effect

In this paper, we demonstrate the design, fabrication, and performance estimation of an integrated Bragg grating (IBG) filter having stressed Si₃N₄ periodic layer over silicon waveguide. The influence of stress-optic effect on the optical performance of the proposed IBG filter is experimentally verified. The proposed IBG filter is fabricated with the different number of grating periods and therefore offers different spectral properties. The proposed filters are designed for a set of target specifications; such as center wavelength, bandwidth, and extinction ratio. The optical performances including temperature sensitivity of the filters are numerically estimated in the absence and presence of stress and are compared with fabricated filter characteristics. The study reveals that the filter, which is designed using numerical simulation considering stress effect, shows the similar optical performance to the fabricated IBG filter. It is also found that the increase of the number of grating periods increases the extinction ratio with narrowing of spectral bandwidth. The IBG filter experimentally demonstrates maximum temperature sensitivity and extinction ratio of 90 pm/°C and 26 dB respectively. The proposed IBG filter offers compact footprint and improved characteristics in comparison to the previously reported filters and finds its potential application in sensing and optical communication. Therefore, the presented work highlights the potency of stress-optic effect in enhancing the capabilities of photonic devices.