The 1940s and 1950s were collectively, known as the "Golden Era" of Sci-fi. During this time science fiction gained wide public attention, particularly through literature.Leaving the obvious talents of H.G. Wells and his historic literary counterparts behind for a moment, it was the Second World War and the creation of the Atomic bomb and other technological advances, which created a stimulus for this golden era.
Whilst the 1950s undoubtedly fared better because of post-war influence, the 1940s film production focussed very much on the war. 191 films were made about the war compared to only 32 science fiction films.
We left the 1930s with a look at th serials of Flash Gordon and Buck Rogers. we had the Flash Gordon serial, of course. We met Dale Arden and Princess Aura in the 1930s, but for the last of the 3 serials, Flash Gordon Conquers the Universe (1940), the actresses changed.
Not on the wiki list is the 1943 film, Captive Wild Woman, but confirmed on the IMdB as horror/science fiction. Here we have Acquanetta, also known as the Venezuelan Volcano, playing Paula Dupree, who is actually a gorilla with transplanted organs from two different women, including a human brain, of course.A year later, Jungle Woman (1944) followed and again we saw the exotic and beautiful Acquanetta (who by the way was born Mildred Davenport, but claims she was born on a native American reservation) playing Paula Dupree aka the ape woman. There was a further film in the ape-woman trilogy, The Jungle Captive (1945), although played by Vicki Lane this time. This film isn't listed as sci-fi by IMDb, but I don't see why - it included the same Paula Dupree character and follows the same storyline. It's difficult to find a good image from the film, so here's sultry Acquanetta in a movie poster for Jungle Woman.
There are plenty of sites out there - too many to link to - just do a search...
Much of the film production in the 1940s focused on the war and there is probably scope for a "war babe" site somewhere on the web, but it won't appear here. What this means is that the 1940s was rather short of sci-fi films and thus babes. In fact, the decade lists only 32 films made in the genre, a far cry from the next decade which boasts over 180!