Nanoparticles of LaFe1-xBixO3 were successfully synthesized through the microwave combustion process (MCP) employing l-alanine as the fuel source. XRD and FT-IR analyses conclusively confirmed the orthorhombic structure of lanthanum ferrite, with the mean crystallite size varying between 56.32 and 25.43 nm. The optical energy gap value, calculated from UV–vis spectra, fell within the range of 1.84 to 2.49 eV. EDX analyses verified the presence of Bi, La, Fe, and O elements. Furthermore, FE-SEM images exhibited the nanoparticles' distinctive aggregated spherical morphology. Notably, VSM analysis showcased the robust diamagnetic behavior of LaFe1-xBixO3 nanoparticles. In photoluminescence's spectra, the samples underwent excitation with a wavelength of 315 nm. The values of Hc (coercivity) and Mr (remanence) fell within the range of 121.98 to 332.39 Oe and 0.1592 to 0.0907 emu/g for LaFe1-xBixO3 respectively. Z-scan experiments yielded values for the nonlinear susceptibility, index of nonlinear refraction, and coefficient of nonlinear absorption. The findings from optical limiting studies serve as additional verification, underscoring the suitability of these materials as promising options for integration into devices, including optical switches and optical power limiters.