It shared some design elements with Anakin Skywalker’s lightsaber, but still had a rather unique feel to it. Yoda lost it during his battle with Emperor Palpatine in the Senate during Star Wars ...

it is Leia who uses the Force (and her lightsaber skills) to save him. Then, Leia is able to block Palpatine's Force-probe into her mind, something the Emperor is actually impressed by.