How the First Laser Was Invented

The foundational 1960 patent by Schawlow and Townes that describes how to amplify light waves to create a laser, moving beyond microwave technology.

What it covers

This patent describes the transition from masers, which amplify microwaves, to optical masers, which we now call lasers. It details the use of a resonant cavity with reflective ends to trap light, allowing it to bounce back and forth through an active medium. This process stimulates the emission of more light, creating a highly focused, single-color beam. It essentially provides the blueprint for using light as a precise tool for communication and energy transmission.

What it doesn't cover

• —Does not cover the use of semiconductor materials for lasers, which were developed later.
• —Does not cover fiber optic cables themselves, only the light-amplification device.
• —Does not cover non-resonant methods of light amplification.

The clever bit

The inventors realized that by using a long, thin cavity with mirrors at the ends, they could force light to travel in a single, coherent direction, effectively turning a chaotic light source into a powerful, directed beam.

Why it matters

This patent is widely considered the birth certificate of the laser. It turned a theoretical physics concept into a practical device that now powers everything from internet fiber optics to medical surgery and barcode scanners.

Real-world examples

• 1.Fiber optic communication networks
• 2.Laser eye surgery
• 3.Barcode scanners
• 4.Laser pointers