What is the approximate wavelength of violet light in air?

The visible light spectrum consists of electromagnetic radiation that the human eye can perceive, typically ranging from approximately 380 nm to 750 nm. Within this spectrum, violet light occupies the shortest wavelength end, generally cited between 380 nm and 450 nm. Specifically, many sources identify the lower bound of visible violet light at approximately 400 nm [1]. To convert this value into micrometers (
m), one must divide the nanometer value by 1,000 (since 1
m = 1,000 nm). Therefore, 400 nm is equivalent to 0.4
m. In contrast, red light represents the longer wavelength end of the spectrum at approximately 0.7
m (700 nm) [1]. Thus, the approximate wavelength of violet light in air is 0.4
m.

Sources

1. [1] https://satheejee.iitk.ac.in/article/physics/physics-visible-light/