A multi-wavelength pulsed mid-infrared laser based on Er:YAG

Highly doped erbium crystals have complex fine energy levels, which can be used to emit lasers of different wavelengths under different conditions. The mid-infrared multi-wavelength laser of erbium ions has not yet achieved stable laser emission. In this study, the rate equation is used, with consideration of mode competition, to design a mid-infrared Er:YAG pulsed laser that emits four wavelengths at room temperature. The gain of the multi-wavelength erbium laser is related to the Boltzmann distribution coefficient. Based on this, the conditions for multi-wavelength output have been calculated and verified in experiments. A four-wavelength stable output mid-infrared pulsed laser based on Er:YAG was produced. This laser may be applied to remote sensing or gas detection. [Display omitted] •A four-wavelength stable output mid-infrared pulsed Er:YAG laser was produced.•The conditions of laser emission were calculated based on Stark effect.•The rate equation introducing mode competition is used.•The laser with simple structure and modulation loss through coating is presented.