ぴかぴか光る[pikapikahikaru] to sparkle
旭光[kyokkou] rays of the rising sun
威光[ikou] power
稲光[inabikari] (flash of) lightning
曳光弾[eikoudan] tracer bullet

栄光[eikou] glory
円光[enkou] halo
炎光[enkou] flame
黄道光[koudoukou] zodiacal light
可視光線[kashikousen] visible ray