JF Ptak Science Books Quick Post
Although electric lamps/searchlights have been militarily used on land and sea since the 1880's (at least), it is still unusual to see light itself displayed as a weapon in a poster. This is especially true when the light is airborne and in real, in-potential-use applications. An earlier image appears in the Illustrated London News of a giant airship illuminating a battlefield, but it is a rather futuristic view of the employment of light as a weapon, and didn't quite come about as an effective tool. (As much as the airship would illuminate of the opponent's night-time position, it also made itself extraordinarily vulnerable--lighting up your enemy's position just didn't make for a practical idea, especially when the notions of bombing and night bombing came into being.)
In this first image below, there is a strong beam emanating from an aircraft in 1917--how it is generating such light, and whether it was conceivable to have it light enough to be on the aircraft, I don't know.
Conversely, the searchlight coming from the military (battle-)ship could certainly have supported the machinery to produce any number of effort, though it seems again to be counter-productive, establishing itself as a not particularly fast-moving target to anything on the sea or above (or below) it.
On the other hand, this Swedish movie poster seems to have put the idea to good use (source, here):