:TRT
Thermal relaxation time is the time when at least Half of the thermal energy from the target tissue is dissipated
It means half of the thermal energy from the target tissue is directed away, and this time is need to prevent skin damage, now if we choose a laser pulse for this Target if the laser pulse width is less than that TRT hair follicle, because the temperature reaches a favorable level of about 80 degrees Celsius and does not spread to the surrounding tissue, so the thermal energy is trapped in the hair follicle and with the least damage to the epidermis, it causes maximum damage to the hair follicle
