Optical Spectrum 

The optical spectrum refers to the range of electromagnetic radiation.

The broader optical spectrum includes:

1. Ultraviolet (UV) Light: This is light with shorter wavelengths than visible light, ranging from approximately 10 nm to 400 nm. UV radiation is not visible to the human eye but can have effects like tanning or sunburns.

2. Visible Light: This is the range of wavelengths that the human eye can detect, ranging from about 400 nm (violet) to 700 nm (red).

3. Infrared (IR) Light: This part of the spectrum lies just beyond visible light, with wavelengths from about 700 nm to 1675 nm.

Note : Spectral bands for optical transmission systems located between 850-1675 nm. 

👉 Six Wavelength bands in Spectral band

1) O - Original band (1260-1360 nm)

2) E - Extended band (1360-1460 nm)

3) S - Short band (1460-1530 nm)

4) C - Conventional band (1530-1565 nm)

5) L - Long band (1565-1625 nm)

6) U- Ultra Long band (1625-1675 nm)