In recent years, because of the rapid development persisting in the modern electronic industries, materials with the ability to produce highly efficient harmonic generation have acquired great demand as they are suitable for high-speed devices and the progressing field of optical communication systems. The present work reports the growth, diffraction and spectroscopic features of the pure and Rhodamine B (RB)-doped potassium dihydrogen phosphate (KDP) crystals. The crystals were grown by employing the conventional slow evaporation technique. The XRD and UV–visible spectral studies have been carried out to examine the structural and optical behavior of the grown crystals. An optical microscopic technique has been utilized to explore the surface features of the crystals. Based on the growth features and the observed analytical results, it is authenticated that the RB-doped KDP crystal possesses a better crystalline nature and optical transmittance than the pure KDP crystal thereby it is strongly suggested for the applications of photonic devices.