Low time jitter fiber femtosecond laser based on narrowband spectrum filtering

Abstract

The invention provides a low time jitter fiber femtosecond laser based on narrowband spectrum filtering, uses the intracavity narrowband spectrum filtering process to effectively stabilize the spectrum components of the pulse in the intracavity evolution process, thus obviously suppressing the pulse center wavelength drift, and greatly eliminating the time jitter components coupled by the intracavity dispersion of the center wavelength drift. The pulse with mass chirps passes the narrowband spectrum filter, the time domain width and spectrum width can be reduced in the same time, thus keepingthe average width of the pulse in a ytterbium-doped single-mode fiber to be at a low state, and limiting the pulse time jitter components directly coupled in the time domain at a low level. The femtosecond laser does not need to repeatedly optimize the intracavity pour dispersion measure and the mode locked state, thus realizing low time jitter operation under different pour dispersion conditions;the femtosecond laser is simple in structure, easy to operate, good in repeatability and long-term stability, thus obtaining a practical low time jitter ultrashort pulse sequence.

Description

technical field [0001] The invention belongs to the technical field of ultrafast lasers, and relates to a low time jitter fiber femtosecond laser. Background technique [0002] femtosecond(fs, 10 -15 s) The ultrashort pulse sequence output by the laser has the characteristics of narrow pulse width, high peak power, and good beam quality, and has been widely used in many fields since its birth. In recent years, the development of laser noise theory and the improvement of measurement methods have gradually highlighted the unique low time jitter characteristics of femtosecond lasers, which has promoted its use as a signal source in high-precision distance measurement, pump detection experiments, and clock signal release. field applications. The time jitter of the femtosecond laser is essentially derived from the amplified spontaneous emission noise in the gain medium. This noise component can affect the pulse distribution in both the spectral domain and the time domain, causi...

AI Technical Summary

Problems solved by technology

However, for a fiber femtosecond laser operating at net zero dispersion, its mode-locked state is often not unique, and the time jitter level between different states will have a relatively large difference

Therefore, the appearance of the low time jitter state often requires repeated optimization of the dispersion amount and the mode-locked state in the cavity, which is difficult to adjust

In addition, the pulse evolution process is easily affected by perturbation inside and outside the cavity, resulting in irregular jumps in the working state of the laser between different mode-locked states, and even multi-pulse operation, which greatly reduces the repeatability and long-term stability of the system. nature, thereby offsetting the practical advantages of fiber lasers

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