Numerical And Experimental Study On Coherent Combining Of Double Cladding Multi-Core Photonic Crystal Fiber

The high-power fiber laser by coherent combining of photonic crystal fiber is currently one important field of research for photonic crystal fiber . In this paper, the coherent combining of photonic crystal fiber has been studied in theory and experment respectively. The main results are summarized as follows: Firstly, it describes the actuality of the photonic crystal fiber and reviewed the latest progress. Then analyze the principles and main characteristics of photonic crystal fiber laser. and pointed out that the double clad fiber laser has its irreplaceable advantages in the researchand application of laser beam coherent combination due to its inherent properties suchas compact structure for convenie- nt addition, high beam quality and etc., from which the paper's conception is.Secondly, With the coupled-mode theory it analyzes optical transmission characteristics and working mechanism of double cladding multi-core photonic crystal fiber, it derived the relationship between the optical parameters and performance.These theories above can be proved on the laser output parameters analog design and analysis .Finally, The coherent experiment has been done utilizing self-designed seven-core photonic crystal fiber . In this experiment the relevant datas are : fiber core d is 2.0μm , the pitchΛis 5.0μm , d/Λ=0.4 , there is hexagonal seven core in inner cladding, the diameter of each solid core diameter D are 18.0μm. continuous light source He-Ne wavelength is 632.8 nm . Through changing the angle of incidence of light , the output beam from the core was made to satisfy phase-matched , and it can achieve the seven-beam interference . That verifies the feasibility of coherent with seven-core photonic crystal fiber , which can be demonstrated by multi-core photonic crystal fiber coherence to implement laser output power of effective amplification . The coherent combining technology is one important method to realize the high-power laser . Through the phase adjustment of evanescent wave on 7 beam light , It can implement a coherent synthesis , laser brightness have been greatly improved . And analyzed and measured the coherent power density of the optical that emitted from the double cladding multi-core photonic crystal fiber using coherent combination theory , and provide the theoretical and experimental basis for multi-core photonic crystal fiber to achieve self-coherent synthesize .