Midinfrared quantum cascade detector with a spectrally broad response

A midinfrared quantum cascade detector with a spectrally broad (Δ<i>E/E</i> = 27.3%) response is designed, fabricated, and tested. This detector consists of 26 differently designed active region stages in order to cover a wavelength region from 4.7 to 7.4 <i>μ</i>m. The device could be operated above room temperature and showed peak responsivities of 13 mA/W at 10 K and 1.25 mA/W at room temperature. A background limited detectivity of 1.55×10¹⁰ Jones was seen up to a temperature <i>T</i>_BLIP of 110 K.