Who built the first laser? What are the basic characteristics of laser beam?

• Theodore Maiman built the first laser in 1960.(Ruby laser)
• The following are the basic characteristics of laser beam:
  • coherent→ the photons or waves travels in step or in phase c one another.
  • Collimated→ the laser light travels in one direction
  • Monochromatic → One wavelength or colour is in the visible spectrum
  • High intensity