A. A diamond block
B. Helium-neon gas
C. A ruby rod
D. Carbon dioxide gas
✅ The correct answer is option C.
Theodore Maiman built the first working laser using a ruby rod while working at Hughes Research Laboratories in Malibu, California. It lased for the first time on May 16, 1960.
Theodore Maiman built the first working laser using a ruby rod while working at Hughes Research Laboratories in Malibu, California. It lased for the first time on May 16, 1960.