Combination of micro-cavity and nano-metals using plasmonic effect may create novel optical devices for communications and optical sensing. In this paper, we study the green coherent emission from an erbium-doped silica microsphere pumped at infrared laser beam with wavelength of 976 nm, which can enhance by a metal coating such as gold, platinum, and aluminum. The case of aluminum coating is studied and the high enhancement shown to decrease with time. The threshold of narrow line-width up-conversion emission from erbium-doped Al-coated silica microsphere is of some tens nano-watt pump power. But after one month kept in air the green light emission threshold of this one increases up to mili-watts, that the enhancement is decreased down to some thousand times in comparison with platinum-coated microsphere as a film of aluminum oxide is formed. In addition, the spectra of green light emission from degraded aluminum-coated microsphere changed from single peak to double peaks that mean the cavity of silica microsphere may make from multi-layers.

使用等离子体效应的微腔和纳米金属的组合可以创建用于通信和光学传感的新型光学器件。在本文中，我们研究了在波长为 976 nm 的红外激光束下泵浦的掺铒二氧化硅微球的绿色相干发射，这种发射可以通过金、铂和铝等金属涂层增强。对铝涂层的情况进行了研究，结果显示高增强会随着时间的推移而降低。掺铒镀铝二氧化硅微球的窄线宽上转换发射阈值为几十纳瓦泵浦功率。但是在空气中放置一个月后，这个绿色光发射阈值增加到毫瓦，与铂涂层微球相比，随着氧化铝膜的形成，增强降低到几千倍。