Current work, L-alanine single crystals in the presence of potassium nitrate were grown by slow evaporation method. The unit cell parameters and crystalline structure of the L-alanine crystal were analysed using powder XRD (PXRD) technique. The numerous functional groups and vibrational modes of the grown crystal were identified by FTIR analysis. The linear optical analysis has been employed in the wavelength range 200-2500 nm to find out the optical transparency of the grown crystal. Nonlinear optical efficiency of the grown crystal is 1.12 times superior to the reference crystalline material KDP. The negative photoconductivity of the grown crystal was exposed by photoconductivity analysis. Copyright © VBRI Press.