Nowadays, different techniques are used for the manufacture of LPFG, some of them are the phase mask method or interferometric method, point by point method with ultraviolet light, electric arc method, mechanical method, chemical method, and CO2 laser method. Favorable results have been obtained by applying the technique that uses CO2-laser since it is not as complex as the methods mentioned above. In this work, the design and manufacture of cascade LPGs is done with a CNC CO2-laser machine configured with 10 W laser power, velocity of 20% and 500 pulses per inch. The results of the transmission spectrum in the manufactured devices show significant changes in the transmission spectrum for the cascade gratings, When the number of gratings is greater a varied interference pattern is generated, and more resonance wavelength peaks appear. The proposed method is easy to implement and reduces the manufacturing time of the devices.