Explaining laser-phosphor illumination in projectors (white paper)

A tale of fireflies and sparks

Once upon a time, there was a group of happy fireflies. They were all having the time of their lives, fl ying together high up in the sky. Suddenly, one little firefly felt a bit tired. He stopped flying and fell down. But as he was falling, he sent a spark to his friends in the sky to say goodbye. The spark hit another firefly, and when he got tired, he also sent a spark along to his friends. Now two sparks floated synchronously into the air and struck the next firefly. More and more fireflies started falling, and more and more sparks moved forward on a search for the next happy firefly.

Suddenly, the group of sparks encountered a mirror. ‘Mirror, mirror, on the wall, who is the brightest of them all?’ ‘You are not,’ said the mirror, ‘I can hardly see your light.’ The sparks decided that they would be much brighter if they all came together later and gathered more friends. They turned away from the mirror and started a quest to find more friends by making any firefly they found on their way fall. After a long trip through the swarm of fireflies, they bumped into another mirror. ‘Mirror, mirror, on the wall, who is the brightest of them all?’ ‘Together, you are,’ said the mirror − and the sparks burst through the mirror, out into the open as the brightest light anyone had ever seen.

Replace the word ‘firefly’ with ‘electron’ and ‘spark’ with ‘photon’, and the story above describes how a laser works.

Dig deeper

Looking for more info on laser phosphor illumination? Here's a sneak peek of the topics we discuss in our white paper: 

• What is a laser?
• Why is using a laser in projectors a good idea?
• Types of solid-state illumination
• Laser safety
• The future of solid-state illumination