A semiconductor laser logic device with GaAs/Al0.3Ga0.7As double heterostructure is fabricated. A main laser and a control laser are monolithically integrated in the cross-coupled structure in order to bring about optical quenching. This monolithic device is not only capable of conventional linear quenching but also new nonlinear quenching by the in-homogeneous current injection of the control laser. It can be used as a digital optical inverter having small trigger energy. The maximum efficiency of nonlinear quenching is 0.67 times that of the direct modulation of the main laser and 13 times that of linear quenching. Compared to conventional optical inverters based on optical quenching, this nonlinear quenching will improve the efficiency significantly.