Either in the solid state or in the fiber amplifier, femtosecond pulse energy is limited by the thermal and nonlinear effects. Chirped pulse amplification (CPA) solely cannot break the barrier of high peak power and average power. Coherent pulse combination, such as the spatially or temporally divided pulse amplification, has the potential to produce higher pulse energies at high repetition rate. Furthermore, coherent pulse stacking from high repetition rate, high power fiber amplifier may even surpass the chirped pulse amplification and produce many order higher pulse energy with high repetition frequency.