there are different approach to get this result, first if you have the light source modeled or is a face of a complex profile, you can use a surface with the luminance channel on like the glass lamps surface (make a test with something simple like a cube and add this surface and render it to see the results, don't forget to turn on illuminating surfaces.
Or you can make it using area lights using the line shape and making the light visible.
Here is a pic, the one in the floor is using the lamp surface applied to a material, the vertical light using the area light.