Quantum detection element with low noise and method for manufacturing such a photodetection element

A quantum photodetection element for an incident radiation in a spectral band centered around a central wavelength λ0, exhibiting a front face intended to receive said radiation, and comprising:

• a stack of layers made of semi-conducting material forming a PN or PIN junction and comprising at least one layer made of an absorbent semi-conducting material with a cutoff wavelength λc>λ0, the stack of layers made of semi-conducting material forming a resonant optical cavity, the resonant optical cavity being a waveguide;
• a structure for coupling the incident radiation with the optical cavity comprising a diffraction grating on a front face and/or a rear face define as on a side of the optical cavity opposite to a side supporting the front face, to form:
• a guided-mode resonance at the central wavelength λ0 allowing absorption of greater than 80% in the absorbent semi-conducting material layer at said central wavelength;
• a minimum of absorbtion at the radiative wavelength λrad, where the radiative wavelength λrad is the wavelength for which, at operating temperature, the rate of radiative recombination is a maximum.