A novel method for high power optical amplification of ultrashort pulses in IR
wavelength range (0.7-20 Ãm) is disclosed. The method is based on the optical parametric
chirp pulse amplification (OPCPA) technique where a
picosecond or
nanosecond mode locked
laser system synchronized to a
signal laser oscillator is used as a pump source or alternatively the pump pulse is created from the
signal pulse by using certain types of optical nonlinear processes described later in the document. This significantly increases stability, extraction efficiency and bandwidth of the amplified
signal pulse. Further, we disclose five new practical methods of shaping the temporal and spatial profiles of the signal and pump pulses in the OPCPA interaction which significantly increases its efficiency. In the first, passive preshaping of the pump pulses has been made by a three wave mixing process separate from the one occurring in the OPCPA. In the second, passive pre-shaping of the pump pulses has been made by
spectral filtering in the pump mode-locked
laser or in its
amplifier. In the third, the temporal shape of the signal pulse optimized for OPCPA interaction has been actively processed by using an acousto-optic programmable dispersive filter (Dazzler) or
liquid crystal light modulators. In the fourth alternative method, the signal
pulse intensity envelope is optimized by using passive
spectral filtering. Finally, we disclose a method of using pump pulses which interact with the seed pulses with different
time delays and different angular orientations allowing the amplification bandwidth to be increased. In addition we describe a new technique for high power IR
optical beam delivery systems based on the
microstructure fibres made of silica,
fluoride or
chalcogenide glasses as well as ceramics. Also we disclose a new optical
system for achieving
phase matching geometries in the optical parametric interactions based on diffractive
optics. All novel methods of the ultrashort optical pulse amplification described in this disclosure can be easily generalized to other
wavelength ranges.