The optical range in wavelength refers to the portion of the electromagnetic spectrum that is visible to the human eye. It covers wavelengths roughly between 400 nanometers (nm) to 700 nanometers (nm). In terms of color perception, this corresponds to violet at the shorter end of the range and red at the longer end of the range.
The visible spectrum can be divided into the following approximate wavelength ranges, along with their corresponding colors:
- Violet: 400 nm to 420 nm
- Blue: 420 nm to 490 nm
- Green: 490 nm to 570 nm
- Yellow: 570 nm to 590 nm
- Orange: 590 nm to 620 nm
- Red: 620 nm to 700 nm
These wavelengths represent the colors we perceive when light of different wavelengths enters our eyes. Beyond the shorter wavelength of violet, there are ultraviolet (UV) rays, and beyond the longer wavelength of red, there are infrared (IR) rays. Both UV and IR are not visible to the human eye without specialized equipment.
The optical range is essential because it allows us to perceive and interpret the world around us based on the different colors of light emitted or reflected by objects. It also plays a crucial role in various scientific fields, including astronomy, optics, and the study of light and its interactions with matter.