The phosphate glasses doped with rare earth ions have been widely used in laser mediums and optical filter materials for their outstanding optical and spectrum characteristics.
稀土掺杂磷酸盐玻璃具有优异的光学和光谱特性，在激光介质材料、有色滤光材料等领域中有着重要的应用。
2
These bulbs are designed to filter out the yellowish spectrum, hence emitting a whiter light which increases visibility at night.
这些灯泡是被设计来滤除黄光谱，因此发出一个白光增加能见度的夜晚。
3
Digital filter is the basic arithmetic of language, picture processing, model recognition and spectrum analysis.