English title

In this paper, a quantum well infrared photodetector based on cascade structure is proposed which is capable of
simultaneous detection of two different wavelengths in mid-infrared region. The active region of this photodetector
is monolithically sensitive to both wavelengths and the electron transport system is designed to transport electrons
excited by two different wavelengths. By attaching a capturing well to the active region a common transportation
path for electron excited by two different wavelengths is realized. Calculated values for responsivity and detectivity
in this structure are: R ( 6.85 m) 67.5mA W 1 l = m = , R ( 12.35 m) 118.5mAW 2 l = m = , * ( ) 7
1 D l = 6.85 = 6.89´10 J , * ( ) 8
2 D l =12.35 =1.2´10 J
at 120K temperature, respectively.