Because gallium arsenide has a high emission rate (it amplifies light efficiently because its bands line up), its total photon emissions easily outpace its absorptions.

• 由于砷化镓发光效率很高（因为能带呈正对排列，所以可以很有效率地放大光），因此其光子发射总数很容易就可以超过其吸收总数。