What do you mean by saying 一种？ 一种means: a kind of. 他refers to a man. 他们refers to a group of persons. 它refers to something like a plant, an animal, or a thing. 它们is the plural form.

I'm not quite sure what you exactly want to express, but I can get the main idea. For grammar, there's no mistakes. However, in Chinese, we usually use 它 as pronoun for things that are not alive. Therefore, in this sentence, you want to use 它 instead of 他 as pronoun for 光(light). 他is the pronoun for male person, the same as "him" in English. Another thing is, I don't understand what you want to say by “一种！”, because 一种 means "a kind of" in Chinese. It cannot be a independent sentence by itself.