紅外燈是否一定有紅外線？

紅外燈吾知你係講正式叫Laser既紅燈丫,,

定係紅外線(Infrared)既燈,,

如果你講槍上面果盞紅燈,,

咁果個只係波長630-680nm既可見光,,

如果你講發出紅外線(Infrared)既燈,,

個波長係大過780nm!

This is not always true. All depend on the porduction mechanism of the red light.
If the red light is produced by incandescence (i.e. because of temperature) which is associated with a continuous spectrum , then there is infared in the spectrum.
However, if the red light is produced by non-thermal excitation of atoms (e.g. in a discharge tube) with the emission of line spectrum within the red light region, infrared may not be present.