High-peak-power single-frequency narrow-linewidth nanosecond fiber laser based on a triangular pulse

A high-peak-power single-frequency narrow-linewidth nanosecond fiber laser based on a triangular pulse, wherein the laser includes:

• pulsed laser generated by the laser seed injecting into a first power pre-amplifier through a first isolator, and then injecting into a second pre-amplifier and then injecting into a power amplifier;
• wherein triangle-shaped pulsed laser with fast rising edge is obtained by using electro-optic and acousto-optic modulator to modulate continuous wave single-frequency laser or a single-frequency semiconductor laser directly modulated by radio frequency signal;
• single-frequency triangle-shaped pulsed laser is employed as the laser source according to the characteristics of narrow intrinsic linewidth and suppression of linewidth broadening caused by SPM, and the power of pulsed laser is amplified through the MOPA system;
• wherein the pulsed laser seed generated through directly modulating single-frequency semiconductor laser comprises:
• the single-frequency semiconductor laser generates a triangle-shaped pulse sequence with preset peak-power, pulse repetition frequency, rising time, falling time, and corresponding FWHM of the laser pulse, which is directly injected into a second core pre-amplifier through a fifth isolator, and then injected into a second AOM;
• and
• the second core pre-amplifier is used to increase the peak power of the pulse sequence and compensate the losses introduced by the AOM;
• the AOM is synchronized with the single-frequency semiconductor laser to further filter out CW components and in-band amplified spontaneous emission to obtain a single-frequency pulse seed.