High power air-clad photonic crystal fibre laser

Abstract

An Ytterbium-doped photonic crystal fibre laser is demonstrated with a 100 microm2 core area and single transverse mode with an output efficiency of 30 %. Double-clad PCF laser structures are demonstrated with pump cladding NA greater than 0.8 and output power up to 3.9 W. Such lasers are potentially scalable to high power.

Numerical modelling of self-heating effects on guiding modes of high-power photonic crystal fibre lasers

“…Photonic crystal fibre lasers (PCFLs) that are also called holey fibre lasers or microstructure fibre lasers have gained much interest due to their ability in generating high power outputs with considerable stability, excellent beam quality, compactness, and maintenance ease [1,2]. The general structure of such fibres consists of air holes arranged in a twodimensional triangular pattern running through the whole fibre length.…”

Ytterbium doped phosphate glass photonic crystal fiber laser

“…In case of single frequency operation, PCF laser fibres with double−clad structure are more efficient than step−index fibres if the air−cladding is implemented. For silica PCF, laser fibre length can be limi− ted to few meters or parts of meter [1][2][3][4][5] but step−index laser fibre need to be usually tens of meters to provide similar high power operation [6][7][8]. Additionally, due to the natural ease of scaling PCF structures, the LMA fibres lasers manu− facturing is possible [9].…”

A Large-Core Compact High-Power Single-Mode Photonic Crystal Fiber Laser

“…H IGH-POWER fiber lasers have recently been the subject of intense research [1]- [7]. Good beam quality, robustness, and relative ease of manufacturing are important characteristics of these lasers.…”

“…In [3]- [6], the desired step in the index of refraction is achieved by controlling the refractive index of the core by choosing appropriate glass host and dopants. Alternatively, [7] suggests a core constructed from a combination of many doped and undoped spots. The effective index of refraction of the core can be controlled by the ratio of the area of doped spots to that of the undoped.…”

“…The collection of these doped and undoped spots creates an effective refractive index that is close enough to that of the cladding. However, [7] reports that only 10% of the total area of the core is doped which is not very efficient. None of the solutions above genuinely employs the novel concept of PCF and can all be applied to regular double-clad fiber lasers.…”