When was the first laser built and by whom?

The first laser was built in 1960 by Theodore Maiman at Hughes Research Laboratories. This groundbreaking invention came after several years of research into the principles of stimulated emission, which were originally theorized by Albert Einstein in the early 20th century. Maiman's laser utilized a ruby crystal as the lasing medium and produced the first coherent light beam emitted from a laser.

The significance of this achievement cannot be overstated, as it laid the foundation for the development of numerous applications in medicine, telecommunications, and various technologies that rely on laser technology today. The year 1960 marks the official birth of the laser, following extensive theoretical work and experiments conducted in the years prior.

The other options refer to dates or institutions that are not associated with the creation of the first laser. While there were significant developments in the field of optics and photonics occurring in those times, they do not correspond to the landmark moment of the first successful laser operation, which is credited to Maiman's work at Hughes Research Laboratories.