Questions such as this are very difficult to answer because they assume a direct correspondence between writers and the characters they depict. Most often, one cannot easily say whether or not the author is most associated with a particular character. All of this being said, one could argue that Voltaire's philosophical views tend to run along the lines of Martin's.
Pangloss's philosophical optimism, particularly its adoption of a fatalistic, passive attitude toward the world, does not appeal to Voltaire. Voltaire spends the majority of the work ridiculing this philosophical perspective, specifically its tendency to deny empirical evidence. It is essentially not a philosophical system that has any relevance for the world, for it is not informed by experience in the world.
Martin's philosophical outlook, though somewhat gloomy, most closely represents Voltaire's own because of this thoroughgoing "realism." Martin, unlike Pangloss, draws his conclusions about the world from the events around him. He does not stubbornly adhere to a preset philosophy. Martin wants to display for Candide the misfortunes of the world in an effort to "bring him around," in the same way Voltaire wants to show the reader the ridiculousness of philosophical optimism as a viable perspective.
I think he compares his character to Pangloss, Martin and Cacombo all three of them.
I think that Voltaire shows his opinion through both Candide and Martin. He shows how optimism can be foolish, and he mocks Candide, but at the same time, I think Martin is more extreme than what Candide really thinks. I think that Voltaire is trying to show how there is an in between way of thinking, and it is still realistic yet not depressing.
i think is cocombo, but voltaire is not optimist so he wont see it as pangloss
At one point Candide compares the optimism of Pangloss with his own more realistic outlook. Candide specifically says he cannot be optimistic like Pangloss. I am no sure who Voltaire compares his own character with though.