A device for measuring the performance of an optical detector comprising: - a cryostat comprising means for placing it under vacuum and cooling it capable of placing the detector in its anticipated operating conditions; - a holder capable of receiving the detector , secured to the inside of the cryostat ; - means for measuring the performance of the detector ; and - a screen (12a-12b) arranged around the holder capable of limiting the radiation likely to reach the holder in a wavelength range of the detector ; characterized in that the measurement device also comprises: - a single-mode optical fiber in the wavelength range of the detector ; the optical fiber being inserted in an opening of the cryostat and comprising: • a first end secured to an opening of the screen (12a-12b), to project a luminous flux onto all or part of the detector ; and • a second end , external to the cryostat , intended to receive a luminous flux; and - at least two modules (50-52) for generating a luminous flux that incorporate a fibered source capable of generating the luminous flux in the second end of the optical fiber ; the means for measuring the performance of the detector being capable of measuring said performance according to the luminous flux received on the second end ; where a plurality of distinct measurements may be performed by interchanging the module (50-52) connected on the second end . - a cryostat comprising means for placing it under vacuum and cooling it capable of placing the detector in its anticipated operating conditions; - a holder capable of receiving the detector , secured to the inside of the cryostat ; - means for measuring the performance of the detector ; and - a screen (12a-12b) arranged around the holder capable of limiting the radiation likely to reach the holder in a wavelength range of the detector ; characterized in that the measurement device also comprises: - a single-mode optical fiber in the wavelength range of the detector ; the optical fiber being inserted in an opening of the cryostat and comprising: • a first end secured to an opening of the screen (12a-12b), to project a luminous flux onto all or part of the detector ; and • a second end , external to the cryostat , intended to receive a luminous flux; and - at least two modules (50-52) for generating a luminous flux that incorporate a fibered source capable of generating the luminous flux in the second end of the optical fiber ; - a single-mode optical fiber in the wavelength range of the detector ; the optical fiber being inserted in an opening of the cryostat and comprising: • a first end secured to an opening of the screen (12a-12b), to project a luminous flux onto all or part of the detector ; and • a second end , external to the cryostat , intended to receive a luminous flux; and • a first end secured to an opening of the screen (12a-12b), to project a luminous flux onto all or part of the detector ; and • a second end , external to the cryostat , intended to receive a luminous flux; and - at least two modules (50-52) for generating a luminous flux that incorporate a fibered source capable of generating the luminous flux in the second end of the optical fiber ; the means for measuring the performance of the detector being capable of measuring said performance according to the luminous flux received on the second end ; where a plurality of distinct measurements may be performed by interchanging the module (50-52) connected on the second end . <EOS>