HIGH PEAK POWER LOW FREQUENCY PASSIVE MODE-LOCKED ULTRAFAST LASER

摘要

A high peak power low frequency passive mode-locked ultrafast laser, comprising an end mirror (1), a laser gain medium (2), an optical fiber unit (3), a mode locker (4), and an output coupler (5) that are arranged in sequence. Mode field adapters (6) are provided at both ends of the optical fiber. The laser gain medium has the function of generating and amplifying photons. The core area of the optical fiber unit is hundreds to thousands of square micrometers. The optical fiber unit has low nonlinearity and high damage threshold. Two mode field adapters are connected to the optical fiber unit, thereby ensuring that only a fundamental mode LP01 is coupled by means of a free space, and ensuring that the energy of a higher-order mode can be restored to the fundamental mode. The output coupler can reflect light to form a laser cavity, and can also extract a part of impact light from the laser cavity to form a laser output. The ultrafast laser has high peak power and low repetition frequency, is easy to produce, has low production costs, and can directly generate hundreds of KHz to 1 MHz of ultrafast laser light having high repetition frequency and high intensity, without pulse selection and amplification.