Manufacturing Technology And Application Of Fiber Combiner

Fiber laser has the advantages of high efficiency of light conversion,small size,flexible,good heat dissipation,high output beam quality,high stability,suitable for use under high power and so on.It has a great application prospect in the fields of processing,medicine,military and so on.Fiber bundle combiner is one of the key devices in the development of fiber lasers.It is a passive device,which can make power directional transmission.Because it is made of optical fiber devices,can be connected through the way of welding and other devices connected to constitute the current study of high heat of all fiber laser.The fabrication technology of fiber combiner and its application in ultrashort pulse MOPA laser amplifier are studied theoretically and experimentally,the main work includes several aspects:1.This paper briefly introduces the background and significance of the research,and introduces the pump coupling technology of the fiber laser,including side pump and end pump.The development and application of fiber combiner at home and abroad are briefly introduced.2.This paper introduces the theory of fiber bundle combiner.First of all,it is necessary to meet the requirements of the number of N;Secondly,in order to make the pump light can be efficiently coupled into the double clad fiber,it will not cause too much light leakage,The fabrication of combiner needs to satisfy the brightness theorem;Thirdly,the fabrication of optical fiber combiner needs to meet the adiabatic condition,and the adiabatic condition is to design a long enough taper transition zone to ensure that the angle of the pulling cone is small enough;Fourth,when the mode field is similar to the distribution of the Gauss function,the fusion loss can be estimated from the mode field diameter.3.The classification of fiber bundle combiner is introduced.The characteristics of double clad fiber and polarization maintaining fiber are briefly introduced;Secondly,based on the method for making capillary fiber combiner production theory and production methods were studied,including fiber beam process,using 3sae TMS series fiber taper platform for fiber bundle taper,online cutting,using Vytran welding machine welding,coating and other content.The fiber bundle combiner fabricated by the above method is tested.The 915 nm LD of 30 W and 50 W were used to test the pump fiber of the fiber bundle combiner,respectively.Among them(2+1)×1fiber combiner can withstand 25 W,transmission efficiency of 83%;(6+1)×1,7×1 fiber combiner can withstand 50 W,transmission efficiency of 91%.4.The passive mode-locked technology are introduced,analysis of the basic theory of fiber laser pump source,including incentives and necessary conditions and the rate equation and the theoretical analysis of the mode-locked fiber laser principle.This paper mainly introduces the application of fiber combiner in ultrashort pulse MOPA amplifier.Firstly,the development of mode-locked fiber laser and MOPA fiber amplifier is introduced;Secondly,this paper introduces a fiber laser with linear cavity structure based on SESAM mode locking.The oscillator using fiber grating,976/1064-WDM,single-mode ytterbium doped fiber,beam splitter(OC)and the SESAM,the fiber laser is capable of generating 7.9 mW average output power with mode-locked pulse width as short as 17 ps centered at 1064.17 nm and 3dB spectral bandwidth is 1.46 nm.The size of prototype is 200 mm*100 mm*30 mm.The oscillator is used as the light source to construct the MOPA amplifier,and the power amplifier is realized,and the(2+1)×1 combiner and(6+1)×1 combiners are applied in the system.The length of about 3m 10/130 ?m large mode area ytterbium doped double cladding fiber and the length of about 5m 25/250 ?m large mode area ytterbium doped double cladding fiber to achieve two power amplification,finally get the average power is 14.47 W,peak power and ultrashort pulse laser output is 39 kW.The experimental device is made into a fiber laser prototype.