blue light

American  

[bloo lahyt] / ˈblu ˈlaɪt /

noun

1. a band of the visible light spectrum that has a shorter wavelength and produces higher energy than other colors of light: occurring in sunlight and emitted by electronic devices that use LED technology.

2. American History, Usually Disparaging. Also Blue Light a member of a faction of the American Federalist party considered disloyal for opposing the War of 1812: so called from the claim that they flashed blue light signals to alert the British to the presence of blockade runners.

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Etymology

Origin of blue light

First recorded in 1810–15

Example Sentences

In this process, three infrared photons combine into one photon with a higher frequency, effectively converting infrared light into visible blue light.

From Science Daily • Apr. 5, 2026

Low-energy infrared photons do not have enough energy to activate electrons, while high-energy photons such as blue light lose their extra energy as heat.

From Science Daily • Mar. 28, 2026

Most of these children were born during the pandemic and spent much of their infancy quarantined indoors, their earliest socialization filtered through the blue light of tablets and television, Aguet said.

From Los Angeles Times • Jan. 27, 2026

Assistant Chief Constable Lynn Ratcliff said all officers driving police cars will still be able to provide a blue light response to emergency calls.

From BBC • Jan. 7, 2026

It was bathed in a pale blue light.

From "Redwall" by Brian Jacques