Abstract: In this paper, the high-order harmonic generation, which is the result of the interaction of the high power laser with helium and neon gases, is studied theoretically in the presence of a plasmonic field. High-power laser radiation to nanoparticles makes a plasmonic field and the high harmonics are generated using the plasmonic field. For high harmonic generation, a high power laser with an intensity of more than 1013 𝑊⁄𝑐𝑚−2 is required, that using the Plasmonic field, high harmonic can be generated with lasers with an intensity of 1011 𝑊⁄𝑐𝑚−2.The results show that the high harmonic generation cut off point in the plasmonic field is greater than the field of the laser field and cut off point at the helium atom is greater than the cutoff point in the neon. So for high harmonic generation, it's better to use helium gas in the presence of nanostructures.
