Divided-pulse laser regeneration amplification apparatus and method

A divided-pulse laser regeneration amplification method, comprising:

• S1, inputting a signal light comprising injecting a ps-level seed pulse into a divided-pulse laser regeneration amplification component via a signal light coupling component, wherein the signal light coupling component comprises a first half-wave plate, a first polarization beam splitter, a first Faraday rotator and a second half-wave plate placed in sequence, the divided-pulse laser regeneration amplification component comprises a second polarization beam splitter and a third reflector, the second polarization beam splitter is adjacent to the second half-wave plate and is in a same column as the third reflector and the second half-wave plate;
• a first quarter-wave plate, a Pockels cell and a first reflector are successively arranged on a first side of the second polarization beam splitter, and a third half-wave plate, a first pulse polarization separation component and a first non-linear pulse amplification component are successively arranged on a second side of the second polarization beam splitter, the first pulse polarization separation component comprises m polarization separation components arranged at same intervals, where m≥2, each of the m polarization separation components comprises a polarization beam splitter, and a quarter-wave plate and a reflector successively arranged at each of two sides of the polarization beam splitter;
• and a vertical distance between two reflectors in each of the m polarization separation components increases successively in a direction from the first pulse polarization separation component to the first non-linear pulse amplification component;
• S2, performing polarization, beam splitting and pulse separation on the signal light in the divided-pulse laser regeneration amplification component, wherein when performing the polarization and beam splitting on the signal light, the signal light firstly reaches the second polarization beam splitter to reflect S-polarized light, then passes through the first quarter-wave plate and the Pockels cell in sequence, and is reflected by the first reflector;
• a switching period of the Pockels cell is controlled in such a manner that the S-polarized light reflected by the first reflector is changed into P-polarized light after passing through the first quarter-wave plate;
• after the P-polarized light transmits through the second polarization beam splitter, a polarization direction of the P-polarized light is rotated by a set angle by the third half-wave plate, such that the signal light is equally divided into P-polarized light and S-polarized light to achieve beam splitting of the signal light;
• the polarized lights after the beam splitting are injected into the first pulse polarization separation component for pulse separation, and divided by the m polarization separation components of the first pulse polarization separation component into 2m sub-pulses with orthogonal polarization between adjacent sub-pulses and with time delay between sub-pulses;
• S3, amplifying the signal light, comprising injecting the sub-pulses into the first non-linear pulse amplification component, and performing twice pulse signal amplifications and rotating a polarization direction of the sub-pulses by 90° in the first non-linear pulse amplification component to obtain amplified sub-pulses, and then the amplified sub-pulses being returned along an original path;
• S4, polarizing and beam-combining the amplified sub-pulses, comprising re-injecting the amplified sub-pulses into the first pulse polarization separation component for polarizing and beam-combining to obtain a single amplified pulse signal light in an S polarization state;
• S5, regenerating and amplifying the single amplified pulse signal light, comprising:
• the amplified pulse signal light being reflected to the third reflector by the second polarization beam splitter, and reflected back to the second polarization beam splitter by the third reflector, and then successively passing through the third half-wave plate and the first pulse polarization separation component to perform the polarization, beam splitting and pulse separation, and then passing through the first non-linear pulse amplification component for amplification, and being reflected by the first non-linear pulse amplification component to the first pulse polarization separation component to perform second pulse beam-combining to obtain combined signal light which is changed back to the P-polarized state again, and then the combined signal light transmitting through the second polarization beam splitter and re-injected into the Pockels cell to complete one regeneration amplification cycle;
• and
• S6, controlling the switching period of the Pockels cell, repeating the steps S2-S5 of the regeneration amplification cycle on the signal light until gain saturation to obtain regenerated and amplified laser pulse beam, then passing the regenerated and amplified laser pulse beam through the second half-wave plate and the first Faraday rotator of the signal light coupling component, and reflecting the regenerated and amplified laser pulse beam by the first polarization beam splitter to output the regenerated and amplified laser pulse beam.