of grating. First, we studied the reversibility of optical path of grating illuminated by monochromatic light, and then
illuminated by polychromatic light. We found that the optical path of diffraction of grating has partial reversibility.
Using the partial reversibility of optical path of diffraction of grating, we analyzed the spectral combination
characteristic of grating and the bi-grating diffraction imaging effect.
Two gratings consist of an imaging system in which a clear virtual image of an object is formed. The diffraction
properties of gratings have important influence on the information of images. In this paper, the imaging characteristics
of bi-reflection, bi-transmission gratings system and the transmission-reflection grating system are studied. The imaging
process and the quality of images of three systems are compared and some characters are summarized. It is useful for
the deep understanding of bi-grating imaging effect and its new applications.
This paper describes a novel and cost-effective way of guiding natural sunlight to the dark areas of multi-storey
buildings. In this hybrid system, two-axis tracking concentrator collects sunlight radiation by focusing it through Fresnel
lenses onto solar cells which act as the valves of the optical fibers and transform the solar radiation into electricity. When
needed the sunlight can be directly distributed through optical fibers and combined with LED lighting module in
specially designed luminaires. This hybrid lighting system guides the sunlight into the building, and also efficiently
incorporate DC LED light sources so that they can provide supplemental lighting as necessary.
In this paper, we designed series of In<sub>x</sub>Ga<sub>1-x</sub>N/Si hetero-junction solar cells. Key properties of In<sub>x</sub>Ga<sub>1-x</sub>N/Si solar cells
(single junction, double junctions) are simulated by using AMPS-1D software, including I-V characteristic, conversion
efficiency, band structure etc. The In<sub>x</sub>Ga<sub>1-x</sub>N/Si hetero-junction solar cells are compared with the performances of Si
homo-junction solar cells. We also discuss some sensitive performance-related parameters in the preparation of InGaN/Si
hetero-junction solar cells.
In this work, key properties of In<sub>x</sub>Ga<sub>1-x</sub>N tandem solar cells (SCs) (single junction, double junctions and triple
junctions) were simulated by employing AMPS-1D software, including
I-V characteristic, efficiency, band structure,
built-in electric field etc. We compared the results of our simulation with the results of other theoretical
calculations published in the literature and analysed the causes of the differences among these results. We try to find
some useful information related to the important parameters of InGaN SCs, such as the band gap configuration and thickness selection. This work may help the progress in the preparation of the InGaN-based high efficiency solar cells.
A novel experimental instrument of diffraction imaging and its applications are introduced in this paper. This apparatus is composed of movable mechanical parts, optical elements and computer image acquisition system. It can be readily used in the confirmation of bi-grating imaging phenomena and observation of the ordinary transmission hologram displaying with white light source.