Translation for "ray of sunlight after rain"
How about 霽光? As in the Song Dynasty poem: 一夕輕雷落萬絲，霽光浮瓦碧參差。("after a night's worth of distant thunder and myriad raindrops / then the light after the rain shines shimmeringly on the blue-green roof tiles") Not sure there's a single character for this but can check 康熙 (standard classical dictionary).

霽 as a single character refers to the clearing of clouds/rain, but I don't think carries a strong connotation of "light" by itself.