This photo is quite easy to execute.
It was taken using a white background.
I set up the lights so that they only lit the background and did not hit the subjects.
I adjusted the lights so that the background was a true white.
This can be done with flash or constant light:
Change the power or distance to the background if using flash.
Change their distance to the background using constant light. The closer the light is to the background the brighter it will be. The histogram on your camera can help with getting a true white without getting a lot of reflected light on the models.
When you pose models in front of the background, the closer they are to the background the more light will be reflected around the edges of their silhouette.