A novel tunable gain equalizer based on the long period fiber gratings written by high frequency CO 2 laser pulses was demonstrated. The resonant wavelength and resonant peak amplitude of the gain equalizer can be tuned by means of adjusting the temperature and transverse load independently. In addition, the wavelength and the peak amplitude have a good linearity with temperature and transverse load respectively, showing that this tunable equalizer is a practical approach to realize dynamic gain equalization in Erbium doped fiber amplifier systems.