While the hacksmith sabre is as close to the movie ones it is not a light sabre. Because you would need a device capable to generate a laser strong enough to cut through steel and a gravitational pull that pulla back the light so you don't shoot through the whole galaxy.
And if you have the technology to build sth like this a light sabre would be the stupidest thing to build.
Pretty sure that lightsabers are described as being plasma-based even in-universe, rather than lasers. I get that the name can be misleading in that sense.