A reference voltage generator circuit for nonvolatile memory devices is disclosed. The system associates a value with each of the queues, where each of the values relates to an amount of memory associated with the queue. One substrate is stacked over the other to construct a three-dimensional circuit structure. Additionally, the blade is shaped such that more of the blade extends away from a blade holder at the rear balance point than at the front balance point. The device includes a detector operable to contact the second surface of the hot edge ring. The first and second birefringent wedges are respectively fixed to the first and second collimating lenses.