Photonic Switch (1 of 2) (IMAGE) University of California - Berkeley Caption The photonic switch is built with more than 50,000 microscopic "light switches" etched into a silicon wafer. Each light switch (small raised squares) directs one of 240 tiny beams of light to either make a right turn when the switch is on, or to pass straight through when the switch is off. Credit Younghee Lee graphic Usage Restrictions with credit License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.