The present invention relates in particular to the field of lasers and in particular to a laser source having a neodymium-doped crystal (2; 23) or fiber and pumpable by pumping means (3; 25) and a non-linear Raman effect converter stimulated in methane (4; 32), characterized in that the crystal (2; 23) or fiber pumped by said pumping means (3; 25) is able to emit a laser radiation at a wavelength between 1.31 and 1.36 μm and in that the Raman converter (4; 32) is able to convert the radiation generated by the crystal (2; 23) or by the fiber into at least one second radiation (7; 36) with a wavelength between 2 and 2.3 μm.