The longest tenure among national U.S. Dept. of Energy laboratory directors will soon end following Charles Shank’s announcement that he will step down as director of Lawrence Berkeley National Laboratory.

On Monday, Shank announced his intention to leave by the end of the year the position he has held since 1989. A tenured professor in physics, chemistry and electrical engineering and computer science, Shank will return to UC Berkeley as a faculty member.

Shank graduated from Berkeley in 1965 and received his master’s and Ph.D. degrees there in 1969. Before taking over the LBNL, he spent 20 years at AT&T Bell Labs, where he was co-inventor of the distributed feedback laser, a component in fiber optic data transmission.

“Throughout his tenure, Chuck Shank has provided scientific and managerial leadership at the highest standard of excellence at one of D.O.E.’s premier national laboratories,” U.S. Secretary of Energy Spencer Abraham said in a release. “As the longest serving D.O.E. national laboratory director, Chuck Shank is looked up to as a leader by his peers at D.O.E.’s 16 other labs – and respected by all those who have collaborated with him at the D.O.E.”

In a release, Shank thanked his colleagues and current UC Berkeley Chancellor Robert Berdahl, who he said was “one of the most enthusiastic” chancellors in terms of working with the laboratory.

“The opportunity to work with outstanding people in science at Berkeley lab is unparalleled,” Shank said in a release. “Through our work as a Dept. of Energy Office of Science laboratory, we have made a great difference for the nation, opening new questions about energy in the universe, sequencing the human genome, developing nanoscience as a national endeavor and achieving scientific discoveries through advanced computing.”

UC President Robert Dynes said in a release that the University would launch a nationwide search for a new director for the lab.

“I am confident that we will be able to secure a top-notch individual who will continue to foster the highest levels of excellence in the operation of this laboratory, one of our nation’s scientific jewels,” he said.