Tulak is the goateed security chief of the USS Vortex in the Doctor's holonovel Photons Be Free, a harsher fictional counterpart of Tuvok who appears in Author, Author.
Tulak is a holographic character from Photons Be Free, the Doctor's holonovel in the seventh-season Voyager episode Author, Author.
He is the story's version of Tuvok, serving as security chief aboard the USS Vortex under Captain Jenkins. The Doctor's disguise amounts to a change of name and a goatee beard; the character is otherwise instantly recognisable, and is written as a cold enforcer who carries out the captain's orders against the ship's Emergency Medical Hologram without question.
Tuvok and his colleagues object that anyone who plays the programme will take it as a portrait of Voyager's real crew, a concern that grows more pressing when the publisher Ardon Broht distributes the unrevised version.