What nm is a red laser?

Wavelength of Red Lasers

Red lasers are a common type of semiconductor laser that are widely used in various applications such as pointers, barcode scanners, and for alignment purposes. The term 'red laser' refers to the visible red light that these devices emit.

Characteristic Wavelength

The wavelength of a red laser generally falls within the range of 630 to 700 nanometers (nm). This range is within the visible spectrum of light, which is approximately from 380 to 750 nm. The precise wavelength depends on the specific type and purpose of the laser.

Common Wavelengths for Red Lasers

• 632.8 nm: This is a standard wavelength for helium-neon (HeNe) lasers.
• 650 nm: Many red laser pointers operate at this wavelength.
• 670 nm: This is another popular wavelength for red laser diodes.

Types and Uses of Red Lasers

HeNe lasers were once prevalent, but have been largely supplanted by red laser diodes due to their smaller size, higher efficiency, and lower cost. These red lasers are widely used in consumer electronics, educational demonstrations, and as alignment tools in industrial and construction settings.

Importance of Wavelength

The specific application of the red laser often determines its required wavelength. For example, laser pointers used in presentations have a distinctly visible wavelength to ensure that the red dot is clearly seen against a variety of backgrounds. In contrast, applications in scientific instrumentation might require a red laser with a wavelength that corresponds to specific atomic transitions or other criteria.

Note: The visibility of a red laser beam to the human eye can be affected by its wavelength. Red light towards the 630 nm range appears brighter than wavelengths closer to 700 nm, at the same power level, given the spectral sensitivity of the human eye.