Saturable absorber mode locking method and saturable absorber mode locking device

Abstract

The invention provides a saturable absorber mode locking method and a saturable absorber mode locking device. According to the present invention, the interaction between the light and a saturable absorption material is realized by utilizing a pair of large-angle tilted fiber gratings, the defects of the existing saturable absorber mode-locking device are overcome, the high-performance saturable absorber mode-locking device is realized, and the development of an ultrafast fiber laser technology is promoted. The saturable absorber mode locking device is based on a large-angle tilted fiber bragggrating, comprises a first large-angle tilted fiber bragg grating and a second large-angle tilted fiber bragg grating which are sequentially connected in the light transmission direction, and the saturable absorption material is deposited or coated on the optical fiber cladding of the connection area of the first large-angle tilted fiber bragg grating and the second large-angle tilted fiber bragggrating, wherein the tilt angle of the first large-angle tilted fiber bragg grating and the tilt angle of the second large-angle tilted fiber bragg grating are 66-89 degrees.

Description

technical field [0001] The invention relates to the field of optical fiber devices and fiber lasers, in particular to a saturable absorber mode-locking method and a saturable absorber mode-locking device, which is a saturable absorber mode-locking device utilizing the mode coupling characteristics of a large-angle tilted fiber grating Mode devices can improve the performance of traditional mode-locked devices and can be applied to ultrashort pulse fiber lasers. Background technique [0002] Fiber laser has become an important development direction in the field of laser technology with unique technical advantages such as high beam quality, high efficiency, high integration, and high reliability. Among them, the ultrashort pulse fiber laser has the remarkable characteristics of narrow pulse width, high repetition frequency, high peak power, wide spectral range, etc. application and huge market value. [0003] Mode-locking technology is the most efficient and concise way to a...

AI Technical Summary

Problems solved by technology

At present, in order to realize this kind of saturable absorber device, there are mainly two structural design schemes: first, the saturable absorbing material is made into a thin film, which is placed between two optical fiber jumper connectors or between the end face of the optical fiber and the Between the mirrors, this structural design has the following problems: it destroys the all-fiber structure; it is easy to cause mechanical damage to the material; the laser directly acts on the saturable absorbing material and the action area is small, which reduces the thermal damage threshold and makes it difficult to achieve high-quality locking. mode pulse and the device is easily damaged

The micro-nano optical fiber used in saturable absorber devices mainly includes D-shaped optical fiber and side-polished optical fiber. The production of this type of optical fiber requires complex processes and expensive equipment. It is difficult to weld with ordinary single-mode optical fiber in fiber lasers and the loss is generally large. , the proportion of light passing through the evanescent field and material effects is difficult to precisely control and regulate

For tapered fiber, the core diameter of the fiber at the tapered place is very thin and easy to damage, which is not conducive to practical application

Images