Solar cells operating in harsh conditions such as extraterrestrial environment suffer from ionizing UV irradiation from the sun and radiation damages from high-energy particles. Titania (TiO2) can achieve high transmittance in the visible and near-infrared while efficiently blocking UV irradiations. Cerium-doped yttrium aluminum garnet (YAG:Ce) is commercially used as an efficient spectral downconverter in white-light LEDs, and it has also been studied for its potential as a radiation-withstanding scintillator. We propose TiO2 / YAG : Ce thin films utilizing TiO2’s UV cut-off properties as well as YAG:Ce’s downshifting properties as both multipurpose protector and performance enhancer for solar cells.
When a multimode fiber transmits a laser beam, the speckle will form in its output field. A dynamic fiber scrambler
could be used to suppress the speckle. No matter what actual way of suppressing speckle is, such as fiber scrambling or
using a rotating phase plate, the suppression is the result of exerting disturbance in the process of the speckle forming.
We could disturb the phase of the input beam with specific method to weaken the speckle effect. To get a speckle image
formed by a multimode fiber, we simulate different diffraction patterns under different phase conditions using diffraction
model, in which the phase of the input beam is modulated by a rough surface, and then sum them to form the
instantaneous speckle. To study the speckle suppression, we superpose instantaneous speckles, and as a consequence the
final speckle is suppressed. The simulation would help us understand the speckle suppression experiment with the input
beam phase modulation conducted in our lab.