Provided the light is strong enough and is on for long enough Duckweed should grow well in artificial light. I do hope you are not calling a small tank a 'Pond'. A Koi Carp grows to over 24 inches long and so it should really be in a real outdoors pond type situation. That is what they were bred and developed for.
duckweed is a hardy aquarium plant will grow in low light setting,
Duckweed can grow in any water that is good enough to sustain live fish.
Duckweed grow in marshes, swamps, and other damp places.
artificial light
Yes, but artificial light is tricky and expensive.
It will still grow as artificial light is still light.
They grow better with natural light because it is natural every plant needs something natural besides water!
no
yes
Duckweed grows in any temperate to warm climate, all over the world, but doesn't grow in cold areas.
yes
plants need light to survive, it is how they feed themselves, whether it be sunlight, moonlight, or artificial.