InGaAs/InAlAs Multiquantum Well Intersubband Absorption at a Wavelength of lambda = 4.4microns

We report, for the first time, intersubband absorption experiments in doped InGaAs/InAlAs multiquantum well superlattices and observe a resonance peak at a wavelength of lambda = 4.4microns which is in good agreement with theory. This material system may be useful for detectors in the lambda = 3-5microns spectra region.