Theoretical study of a porous silicon cavity based on second harmonic waves formed by ferroelectric crystals for wide range multi-physical and chemical measurement

A metalayer (ML) composed of indium antimonide, ferroelectric crystals and porous silicon with high transmission, sensing properties, wide detecting range, and multiple physical measurements is proposed which optimized by the improved ant colony algorithm (IACO). Due to the quasi-phase matching principle and nonlinear optical properties, the second harmonic waves with high conversion efficiency are successfully generated in the micron operating band, and forms a high and narrow transmission peak for sensing detection. Through analysis using the transfer matrix method which is driven by IACO to accelerate the optimization of structures, the sensing performance sensitivity ( S ), quality factor ( Q ), figure of merit ( FOM ), and detection limit ( DL ) are calculated. The proposed ML demonstrates the capability to measure thickness ( S =18.75, Q =11885, FOM =332 μm ^-1 ), external temperature ( S =4.6 nm/K, Q =7046, FOM =0.049 K ^-1 ), and magnetic field intensity ( S =1332 nm/T, Q =8146, FOM =16.3 T ^-1 ). Additionally, it exhibits an ultra-wide refractive index sensing range from 1 to 5, and excels in detecting hydrobacteria, and viruses with good sensing performance ( S =44000 nm/RIU and 43460 nm/RIU), high Q values (5585 and 6103), and low DL (1.38×10 ^-4 RIU and 1.3×10 ^-4 RIU). This versatile and promising ML design offers possibilities for comprehensive multi-physical and chemical parameter measurements in diverse fields.