Research About Mode-locking With New Materials And New Heat Dissipating Stucture Of One Micron Solid-state And Fiber Lasers

As a part of photonic materials,low-dimensional materials have important applications in solid-state and fiber lasers.Low-dimensional materials are those materials that the dimension is less than three,including zero-dimensional(nanocrystals and quantum dots),one-dimensional(nanowires or nanoribbons)and two-dimensional materials(nanosheets).In low-dimensional materials,the electrons are confined in the finite dimensions(or space),which will contribute to the interesting nonlinear optical phenomena when interacting with laser.The nonlinear properties include saturable absorption,two-photon absorption,three-photon absorption and so on.In low-dimensional materials,two-dimensional materials are widely used in the fields of optoelectronic devices,such as optical modulators and field transistors.Two-dimensional materials include graphene,boron nitride(BN),topological insulators,transitional metallic dichalcogenides(TMDCs),black phosphorus and so on.For lower-dimensional materials,such as some quantum dots materials,owing to have high photoluminescence efficiency,they are often used in solar cell,liquid crystal display(LCD),light emitting diode(LED)and some other fields.Fiber lasers have advantages of high cooling efficiency,simple and compact structure,good capacity of resisting disturbance and so on,while solid-state lasers can produce high power laser output(for the single laser unit)with good beam quality.So lasers have wide applications in military,medicine,material processing,scientific researches and other fields.In some situations,low-dimensional materials can act as saturable absorbers in solid-state lasers and fiber lasers to achieve high pulse energy,ultrashort pulse width and tunable laser wavelength output.Silicon carbide(SiC)is a semiconductor.It has high thermal conductivity and hardness,and can act as an efficient thermal conductive material for heat dissipating in solid-state lasers.It has wide application prospects in high-power and high-beam-quality solid-state lasers with simple and compact structures.Thermal effects are inevitable for laser gain media(such as ytterbium-doped yttrium aluminum garnet)in high power(or high energy)solid-state systems.Thermal lens effect is one of them.To minimize the damage that brought by thermal lens effect,we propose a new kind of thermal lens free solid-state laser structure.This new structure adopts ytterbium-doped yttrium aluminum garnet thin disk as laser gain medium and He gas act as cooling medium.Compared with traditional rotaing-disk laser,we adopt double face cooling method and high-speed rotated-wheel(or use disc)to improve the cooling efficiency and minimize(even elliminate)thermal lens effect in laser gain medium.