What is a photosaber?

Answer 1

There is no such thing as a photosaber. However, you may have been looking for one of these:

Guard Shoto: A guard shoto (also known as a 'lightsaber tonfa') is a rare, perpendicularly-gripped type of short lightsaber with a second handle extending from the main hilt at 90 degrees. Maris Brood wielded two red Guard Shotos.

Shoto: Also known as simply a short lightsaber or occasionally a lightdagger, the shoto is a lightsaber with a smaller than normal hilt the produces a much smaller blade than most lightsabers. Think of Ahsoka Tano's new lightsabers; the smaller one is a shoto.

Answer 2

There is no such thing as a "photosaber." It is possible you meant "lightsaber," which is a fictional weapon from the Star Wars franchise. A lightsaber is a powerful energy sword typically associated with Jedi and Sith warriors.