Effect of polarization sensitivity on ultrasmall silicon-on-insulator-based arrayed waveguide grating for fiber Bragg grating sensor interrogation

Abstract

Polarization sensitivity is an important factor that affects the interrogation of ultrasmall arrayed waveguide grating (AWG) for fiber Bragg grating (FBG) sensor. An ultrasmall 1 × 8 silicon-on-insulator (SoI) AWG with a core size of less than 530 μm × 480 μm is proposed in this study. This ultrasmall SoI AWG exhibits good transmission spectra and high polarization sensitivity. The increased channel numbers and tight structure increase the polarization sensitivity of AWG. Temperature interrogation experiments show that the FBG sensor interrogation is drastically affected when the effect of polarization sensitivity on the ultrasmall AWG is sufficiently large.

SOI Waveguide Bragg Grating Photonic Sensor for Human Body Temperature Measurement Based on Photonic Integrated Interrogator

“…Spreading from the output waveguides of the 1 × 8 AWG, the 1 × 8 photodetector (PD) array enters through the output grating couplers, and the PD array detects the light intensity and converts it into electrical signals, which are transmitted to a computer through DAQ for data processing. We used a method to combine an edge filter with AWG to obtain the wavelength shifts of the Bragg grating [ 19 ]. The reflection spectrum shifts to the right when the external temperature of the Bragg grating increased, while the center wavelength of the VCSEL remained unchanged.…”

“…AWG, the 1 × 8 photodetector (PD) array enters through the output grating couplers, and the PD array detects the light intensity and converts it into electrical signals, which are transmitted to a computer through DAQ for data processing. We used a method to combine an edge filter with AWG to obtain the wavelength shifts of the Bragg grating [19].…”

PLC-Based Arrayed Waveguide Grating Design for Fiber Bragg Grating Interrogation System

“…InP-based waveguide devices, however, exhibit some polarization dependence and necessitates the employment of specialized external polarization processing, adding to the system’s complexity. In 2018, Tianjin Polytechnic University [ 20 ] designed an ultra-small AWG on an SOI substrate with a good transmission spectrum and high polarization sensitivity, with high accuracy in the range of 10 to 50 °C. However, SOI-based waveguide devices are single-polarized, coupling loss with optical fiber is large, and the small process tolerances make it impossible to obtain satisfactory performance.…”