Within a laser tube, every photon

Within a laser tube, both spontaneous and stimulated emissions occur.

Spontaneous emission produces photons in random directions with a slight spread in energy and wavelength due to natural and Doppler broadening mechanisms. Stimulated emission produces photons that travel in the same direction with the same energy and wavelength as the incident photons.

Because spontaneous emission photons are also present within the tube, not every photon travels in the same direction, nor do they all possess the exact same energy or wavelength.

However, all photons are quanta of electromagnetic radiation and travel at the same speed (the speed of light) in the given medium.

Therefore, within a laser tube, every photon travels at the same speed.