invention is preferably a wafer scale process application_number US 66606808 A description fig1 shows a simplified diagram of the operation of a quantum cascade laser according to the prior art the cascade laser differs from conventional lasers by the specificity of its active zone 1 this is formed from a number of periods each consisting of several tens of epitaxially grown layers of semiconductor materials such as for example ingaas alinas gaas algaas or inp when an electric current is injected into this active zone 1 the electrons acquire energy that they restore by the cascade effect each time in the form of a photon the engineering of the material nature of the semiconductor thickness of the epitaxially grown layers etc determines the emission wavelength of the laser the waveguides 2 enable the light output by the laser in the form of a beam 4 to be amplified moreover the active zone 1 and the waveguides 2 are grown on any substrate 3 that provides the function of a mechanical support in general the reflection loss at the output of the qcl laser is around 25 for an inp active zone because of the difference between the refractive index of inp which is about 3 for a 9 u03bcm wavelength and the refractive index of air which is close to 1 notably to limit this loss it is necessary to provide an antireflection treatment on the output face of the laser and to introduce a high reflectivity on the other face for this purpose the imperfect technologies described in the preamble in particular thin film deposition are used at the present time the invention proposes to use what are called u201c artificial u201d materials comprising etched subwavelength structures in order to improve the control of the antireflection and high.