1. The improvement of the performance of fiber laser itself

  How to improve the output power and conversion efficiency, optimize the beam quality, shorten the gain fiber length, improve the stability of the system and make it smaller and compact is the focus of future research in the field of fiber laser.

2. Development of a new type of fiber laser

  In time domain, ultrashort pulse mode-locked fiber laser with smaller duty cycle has been a hot topic in laser field. In frequency domain, broadband output and tunable fiber lasers will become a research hotspot.
  The research of fiber laser has been started since the end of 1980s. Because it can produce ultrashort pulse and has a very broad application prospect, the world has shown great enthusiasm for the research of fiber laser. Compared with other types of lasers, fiber lasers have the advantages of high reliability, simple structure, low price and high conversion efficiency.
  Domestic research in this field is also carried out earlier, both theoretical and experimental, have achieved a lot of research results. However, compared with foreign countries, there is still a large gap. Especially, the research on high performance fiber laser is relatively few, the practical work is far from enough, and the effect is not very ideal. Therefore, it is necessary to further strengthen the research on passive mode-locked fiber lasers.
  The study of fiber lasers began in 1963 when Snitzer first reported Nd,10- doped fiber lasers. Especially in recent years, with the progress in the design and manufacture of optical fiber, the output of fiber laser is increasing, and the CW output power of a single fiber device has increased from 100 watts to kilowatt. At the same time, the high quality fiber with large cladding diameter and large aperture is improved in manufacturing technology, which makes it easy to realize the effective coupling with the pump power of the secondary tube.
  The most significant advantage of fiber laser is its high pump efficiency. generally, the pump conversion efficiency is 70–75%, which is much higher than the solid-state laser (DPSSL) pumped by industrial secondary tubes. Such high conversion efficiency reduces the refrigeration and power requirements of the laser system, can be more compact than the traditional solid-state laser structure, and the whole fiber structure can provide a very strong and reliable packaging design. Moreover, the fiber laser can significantly enhance the beam quality of the output.
  Another important advantage is that fiber laser technology can greatly prolong the device life (compared with DPSSL), which has led industrial laser companies focusing on fiber lasers to increase their investment. Because long-term reliability is very important at the application level. Fiber laser also has other advantages: because the laser medium of fiber laser is the waveguide medium itself, the fiber laser can easily connect with the fiber transmission system efficiently; the core can be made very fine to achieve high power density; the fiber laser has high conversion efficiency and low estrangement value because of its good heat dissipation performance. The output wavelength of fiber laser covers a wide range from 400 to 3400 nm, and can meet all aspects of application needs. It has a good application prospect in industry, commerce, communication, military and medicine.