The Fraxel DUAL 1550/1927 is a cutting edge system that uses two lasers which can improve the appearance of your skin. The 1550nm wavelength improves fine lines and scarring, while the 1927nm improves pigmentation.
The 1550nm penetrates deeper and you would expect more redness...
Your skin should return to its normal status after it is healed - it is not a good idea to put a band aid on the skin that is healing as it could increase the risk of infection, although it is unlikely that this would cause a problem if you did it only once.
For most patients the redness after Fraxel repair should be resolved in three weeks. The redness also depends on the setting used and the nature of an individual's skin. For the best results please find a board certified dermatologist with a great deal of experience with Fraxel.