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We present the basic steps for the study of the linear near field absorption spectra of semiconductor quantum dots under magnetic field of variable orientation. We show that the application of the magnetic field alone is sufficient to induce -increasing the spot illuminated by the near field probe- interesting features to the absorption spectra. [ABSTRACT FROM AUTHOR]

We have studied infrared transient absorption spectra of CuCl QDs grown inside a NaCl matrix under tunable UV laser excitation on resonance with the confined excitons. In addition to the transient excited-state absorption, there appears induced IR absorption with lifetime much longer than that of the confined exciton. The peak energy remains at ∼ 0.3 eV regardless of the QD size. The optical density is proportional to the square root of the UV laser power. The decay of the induced absorption is logarithmic on time and is accelerated by the irradiation of light below the band gap. We assign this absorption to be originated from the electron-bound defect center called I[sub e] center generated in the NaCl side of the interface and discuss it phenomenon in relation with photo-irradiation effects, such as photofatigue, blinking of the luminescence and hole burning. [ABSTRACT FROM AUTHOR]