How does light work in Heaven?
It doesn't, because photons are particles that exist in material creation. "Heaven" in the sense of "the abode of God" isn't a place, it's the sublime reality of God as the transcendent ruler over all things. That is why Solomon after building the Temple says, "The heavens, not even the heavens of heavens can contain You". It's why we read in the Prophet Isaiah, "The heavens are My throne, and the earth My footstool".
In the ancient world where the cosmos was conceived as there being the earth and then the heavens above the earth--the sky, the place where the sun, moon, and stars are observed from an earthbound observer to speak of God as in the highest of heavens (and, even more than that as the quote from Solomon shows) it to speak of God's utmost glory and power. God is above everything we can see.
In the pagan religions of the nations surrounding Israel, the gods were identified with the celestial realm--the sun, moon, stars, etc. Which is why they worshiped the celestial bodies as divine, or as manifestations of the divine. The "wandering stars" i.e. the planets were identified often with some of the most important deities, which is why the Greeks and Romans assigned to them the names of their gods: Mercury, Venus, Mars, Jupiter, and Saturn.
The ancient Israelites, in contrast, by their experience and encounter with the true God who made all things, knew that their God wasn't like those false gods. He wasn't part of the heavenly sphere, but above it, He made it. He made the sun and moon and stars. These celestial bodies aren't gods, they aren't divine powers, they are mere impersonal creatures.
God is bigger than His creation, above it. And the language which our spiritual ancestors had available to them, and which they used in Scripture, was to speak of God being more than, bigger than, higher than all else. The heavens were the highest, biggest, greatest, most majestic thing they could conceive--it was all this glory and light and phenomenon happening way up there, but that wasn't God, God was above that, He made that stuff.
That's what "heaven" in reference to God means. So no, there is no "light" in heaven, except the Uncreated Light of God--which isn't literal light, but refers to God's divine glory. The "light" that poured out of Christ at His Transfiguration, the blinding "light" that Moses experienced on Mt. Horeb, isn't created light, it isn't photons, it's the unfathomable light of God about which St. Paul writes about, "He dwells in unapproachable light" (1 Timothy 6:16).
-CryptoLutheran