We described the characterization of an acousto-optic modulation system and the optimization of the set up to improve the efficiency of diffraction in single and double-pass configurations.In the singlepass configuration, the system consists of an acousto-optic modulator, a voltage-controlled oscillator (VCO) and a radio frequency amplifier, in which the diffraction efficiency and the optical power of the diffracted beam were characterized in the function of the applied radiofrequency.Additionally, taking as a reference the need to correct the variation of the diffraction angle that may occur when the system is modulated in frequency in a simple step, its correction is presented by means of the implementation of the configuration in double step.The double-pass configuration consists of a VCO that controls the incoming acoustic signal to the modulator, a modulator which diffracts the incident light and this passes through a retarder sheet to avoid the retroreflection of the beam; Then, using an iris, only order 1 of diffraction of the beam was allowed to pass and a plane mirror was used for working in the infrared which directs the laser in the second pass of it in the modulator.Once the double-pass system had been optimized, the diffraction efficiency curve was obtained.This work is presented as an updated guide for the implementation of an acousto-optic modulation system in a double-pass configuration.