E-Locus - Ιδρυματικό Καταθετήριο Πανεπιστημίου Κρήτης - Light amplification and lasing in nanostructured hybrid materials

Αρχική Light amplification and lasing in nanostructured hybrid materials

Αποτελέσματα - Λεπτομέρειες

[Προσθήκη στο καλάθι]

Κωδικός Πόρου

000352672

Τίτλος

Light amplification and lasing in nanostructured hybrid materials

Άλλος τίτλος

Ενίσχυση εκπομπής και δράση λέιζερ σε νανοδομημένα υβριδικά υλικά

Συγγραφέας

Στασινόπουλος, Ανδρέας

Σύμβουλος διατριβής

Φωτάκης, Κωνσταντίνος

Μέλος κριτικής επιτροπής

Αναστασιάδης, Σπύρος
Άγγλος, Δημήτρης

Περίληψη

In this thesis, the laser action from new nanocomposite (mainly based on zinc oxide (ZnO)) and bifunctional (scattering and amplifying) materials and the determination of the photophysical mechanisms that are responsible for the observed laser emission, which was termed as random laser, are studied. The required optical feedback for the random laser action is obtained from microcavities that are randomly formed among the scatterers. The matrix (organic or inorganic) keeps the nanoparticles dispersed while in parallel it offers its mechanical properties (i.e. flexibility). For the optical characterization and the study of the random laser phenomenon the samples are optically pumped with pulsed laser sources of proper wavelength and temporal pulse width. The experimental measurements that took place regard the spectral recording of the emitted photoluminescence and the random laser emission as a function of various pumping conditions (excitation energy density, temporal pulse width, excitation wavelength, sample temperature, excitation surface area, etc), the measurement of the temporal decay of the emission, the recording of random laser modes and finding the optimal condition for their appearance, the real-time measurement of the coherence length of the random laser emission and the understanding of the random laser phenomenon, the study of the gain and feedback mechanisms and as a whole the study of the random laser action in the new nanohybrid ZnO materials that we have produced. Finally, there was a side-project on carbon nanoparticles for which we performed their optical characterization; absorption, fluorescence and quantum efficiency measurements.

Φυσική περιγραφή

196 σ. : εικ. ; 30 εκ.

Γλώσσα

Αγγλικά

Θέμα

Coherence

Correlation

Excitation

Inversion

Laser Modes

Nanocomposite

Random