Advances in ultrashort divided-pulse amplification systems

The new development of using divided-pulse amplification system in controlling the fiber nonlinearity, enhancing the pulse energy and breaking through the damage threshold of gain material was reviewed, including the basic types of pulse divider and optical arrangement of amplifiers. The latest advances in high repetition rate, high power Er-doped fiber divided-pulse amplifier was introduced. Based on the double-pass configuration and multi-stage pulse divider, nonlinear amplification and pulse compression were achieved simultaneously, resulting in frequency-doubled output pulses with an average power of hundreds of milliwatts and pulse width less than one hundred femtosecond at 780 nm. This divided-pulse Er-doped amplification method has proven a valuable tool to develop compact, user-friendly and environment stable femtosecond source, which provides an alternative to Ti:sapphire laser in applications to the generation of Terahertz radiation, biological imaging and optical nonlinearity.