Here’s one way using built in effects.
WARNING – FLASHING GRAPHICS BELOW
Create a black solid and add the “Lens Flare” effect. Move the Flare Center to the far left side of the screen.
Add a gaussian blur… let’s say 200 for the blurriness. Check “Repeat edge pixels”.
Add a glow. Let’s say 260 for radius.
Duplicate the layer. Move that flare to the right side. Set the blending mode of the top one to “Add”. Add a white solid to the top of the comp at 10% opacity for a general wash, set it to “add” as well.
Precompose those three layers.
Set the precomp blending mode to “Add”.
Add a tint effect to the precomp. Change the black color to a saturated blue.
Add a levels or curves effect, and animate the brightness along with the opacity of the layer.