Yes and everyone can see 1310nm communication lasers (such as SFP modules) emitting red light when looking directly into one. It's because most IR lasers and LE

Yes and everyone can see 1310nm communication lasers (such as SFP modules) emitting red light when looking directly into one. It's because most IR lasers and LEDs are not really monochromatic. The visible light is very useful for debugging and there's no practical advantage in buying lasers or LEDs emit only one wavelength