https://www.selleckchem.com/products/azd5305.html Color-rendering manipulation of solar cells is drawing increasing interest, since the integration of color displaying can promote various advanced applications. However, the dual functionality of high-performance operation and easy processing remain a challenge. Here we propose a colorful perovskite solar cell (PSC) based on purely planar layers. The photonic crystal (PC), which does not interfere with the PSC processing, enables the display of high-purity colors and maintaining the number of PC layers at 4-6. The fabricated PSC with a four-layer PC successfully displays red-green-blue (RGB) colors, with the power-conversion efficiency of 10.94%, 11.01%, and 13.70%, respectively. Further study indicates that by employing a six-layer PC the PSC can obtain excellent color-displaying effect with the color gamut up to 81.8% of the standard RGB. It also shows that the design has a good tolerance to the deviation of layer thickness.It is well known that the Hong-Ou-Mandel (HOM) effect can be realized on beam splitters (BSs) in the form of coupled waveguides. It is believed that in this case, the theory is similar to HOM interference on conventional BSs. In this work, it is shown that if a BS is used in the form of a coupled waveguide, the theory of HOM interference can differ significantly from the known one. It is shown that even in the case of completely identical photons, the visibility of V can essentially differ from unity. The developed theory must be taken into account in quantum optical schemes, where BSs are represented mainly as coupled waveguides.We demonstrate a high-efficiency thermo-optic (TO) tunable micro-ring resonator in thin-film lithium niobate. Thermal insulation trenches around the heated micro-ring resonator and the underlying silicon substrate significantly reduce the heating power consumption and improve the tuning efficiency. Compared to conventional TO devices without thermal insulation trenches,