New technology promotes fiber-optic laser development

Recently, the progress that the headway that place of fiber-optic laser technology gains high power and Gao Liang spend diode of fiber-optic coupling laser is close together and relevant. Today, be based on fine of standard business consumed, component and 976nm laser diode, fiber-optic laser has become the kilowatt form that implements output wavelengh to be 1 M likelihood. Person eye safety is fiber-optic the development of laser technology, make clear be based on mix into Thulium fiber-optic with technology of diode of laser of 790nm pump riverside, kilowatt level achieves probably in the future in 2 M place fiber-optic laser. Diode of high power laser diode of laser of pump riverside module the commonly used interface between pump riverside module and fiber-optic laser is a diameter 100 ～ 200µThe fiber-optic end fine of M, its typical numeric aperture is 0.

12 ～ 0.

22. These diode end fine are received normally fiber-optic close bundle implement, with enhancing pump riverside power further (see a picture 1) . Long-term since, of diametical 100 M fiber-optic use at coupling laser diode only single pipe. Inside the wavelengh range that exceeds 900nm, the power level that fiber-optic coupling sheet provides has increased 10W above steadily, but inside the wavelengh limits in 790 ～ 810nm, its power is less than 10W. Although at present sheet is in charge of to 100/105µThe coupling efficiency with fiber-optic M amounts to 90% above, but because single pipe is on perpendicular direction not cram is fiber-optic (academic factor is 10 ～ 20) , make this kind of means did not reach maximum in brightness and respect of fiber-optic coupling power. Fiber-optic laser is accelerating kilowatt class high power development, rise as what output power, this needs the pump riverside module of taller brightness, also need the diode array that many glow nod subsequently. Array of these diode of new-style tall brightness have increasing pitch to grow, match photograph of small optical cell to be united in wedlock with tall brightness, those who make the many glow in odd array nod coupling to enter diametical 100 µm is fiber-optic in become a possibility. Use the newest achievement of this kind of method, revealed through a kind firm and reliable, the power output that obtains 50W through the device of industrial test and verify, limit of its theory power exceeds 100W. Because use this kind of array, this kind of design realized the tall brightness module inside 790nm wavelengh limits (output 20W like 5mm array, 10mm array outputs 40W) . Through wavelengh the lock is decided and undertake protective to the back reflex of fiber-optic laser, system of free space optics can be added in module before. To achieve the output power of kilowatt class, fiber-optic laser is used advocate oscillation power magnifies (MOPA) structure, this need has higher power (be more than 200W) pump riverside module. Because this is planted,the fiber-optic diameter that uses in the design can increase 200 µm, the Gao Liang that mentions in above paragraphs spends much array module, can build module as compose (Building Block) in order to enhance power. Pass optical overlay and polarization coupling, but many unit (6 reach 10) coupling is 200 µm, numeric aperture to Chan Genzhi diameter for 0.

Of 2 fiber-optic in. The quantity of heat that laser diode produces makes heat sink through a big copper send out go out, can use thereby industrial water or high-powered semiconductor refrigeration implement undertake cooling, and do not need to use cooling small passageway to fold what layer place needs to go ionic water. A module of 976nm fiber-optic coupling that has array of 4 laser diode, the power that can exceed 200W through the fiber-optic implementation of 200 µm is outputted (see a picture 2) . To gain more high power, reduce cost and increase brightness, need undertakes optimizing to diode laser array, include to reduce the complexity of small optical system among them. A kind of of company of laser of German DILAS semiconductor new-style design showed the 500W power output that through 200µm fiber-optic coupling module obtains 2007, this kind of design confirmed fill factor (glow nods sectional dimension to divide with span) two kinds of main character come true in 10% limits internal energy: Because removed hot interference, every output power that delivers spot and single pipe are adjacent; Nod sectional dimension and span as a result of glow than be 1: 10, because this is in slow axis direction (horizontal way) achieved result of optimized collimation of beam of light. Through array of lens of will slow axis and collimation of a fast axis (FAC) lens is combined simply, all glow of odd array are nodded can what coupling is 200µm to a diameter is fiber-optic in. The array that passes appropriate FAC lens and low Smile effect (horizontal deviation does not exceed 0.

1 M) , what be 200µm to a diameter is fiber-optic and character, theoretic can realize 30 ～ at most the optical overlay of 40 array. But to increasing power character, 20 diode array is more actual, its output power to will exceed 1200W. When power exceeds hundreds tile, enter fiber-optic coupling efficiency and fiber-optic connector medicinal powder hot, will be the firstest issue. Fiber-optic laser is based on 1m high power riverside of business consumed fine, pump closes bundle implement and the system of MOPA of kilowatt class high power of diode of pump riverside laser, the power that can achieve 225W is outputted. The general power of module of 6 pump riverside is 1.

2kW, be entered by combination a taper is fiber-optic bundle, next pump ytterbium of Pu Yigen mix into (Yb) double bag layer is fiber-optic, this are fiber-optic the diameter is 400µm, numeric aperture is 0.

46 (see a picture 3) . Be based on the riverside of pump of tall slope efficiency of module, easier implementation has this kind of fiber-optic laser quality of single standard beam of light, exceed the power output of 1kW. The advantage of structure of this kind of MOPA depends on having the flexibility that inputs seminal source to differring and compatibility. American Nufern company already research and development of this kind of amplifier protect slant (PM) edition, can provide narrower than other design clue wide. Fiber-optic amplifier already was in current kilowatt level next 8GHz line is broad undertaking test, as suffer technology of scattering of the Li Yuan that stimulate cloth to be applied to higher power level, fiber-optic amplifier will achieve kilowatt level probably wide output of odd frequency line. Although to data of a lot of industries treatment is told, the line is broad the control with the polarization is not significant, but apply to a lot of military affairses (overlay of beam of light) will tell, crucial this at 2 o'clock. And we return discovery, on same power standard, the oscillator that these high power magnify class compares them is more effective, it is no matter still change efficiency to look from total power from laser diode cost, this can say is an advantage. Current, the efficiency of changeover of light produced by electricity of diode of tall brightness 976nm is about 45% , efficiency of total changeover of light produced by electricity is the amplifier that obtains from this about 35% . As the improvement of laser diode material, light produced by electricity changes efficiency to return hopeful to rise further. Person eye safety is fiber-optic laser is the closest, the development of fiber-optic laser uses most high power mix into ytterbium is fiber-optic, pump riverside wavelengh is in 9xx Nm, output wavelengh is in about 1080 Nm. However, the job is in wave band of person eye safety (wavelengh is more than about 1.

4 µm) high power, efficient fiber-optic laser, also be the topic that military affairs, industry and medical application are interested in. Recently, the mix into Thulium that the job controls in 2 M (Tm) the headway that fiber-optic laser gains, had made the output power of individual and fiber-optic laser is close to 1kW. Realize the key of afore-mentioned 1kW power to depend on: Fiber-optic to Thulium of pump riverside mix into 790nm laser diode undertakes optimizing, the high power that wants to realize place to need below efficiency of taller light produced by electricity especially and tall brightness (see a picture 4) . Technology of riverside of this kind of pump and efficient the newest progress photograph with mix into fiber-optic Thulium is united in wedlock, had made fiber-optic laser technology achieves person eye security of 25% (power is changed) efficiency. Mature as continuity of laser diode material, the fiber-optic laser of these new job wavelengh also will get be improvemented further. CNC Milling