A kind of last conversion optical fiber laser of blue green light output
Technical field
The present invention relates to a kind of fiber laser, especially relate to a kind of last conversion optical fiber laser of blue green light output.
Background technology
The blue green light wave band of laser value that has a wide range of applications in fields such as high density data storage, submarine communication, large scale display, three-dimensional display, detection, life science, Fibre Optical Sensor, laser medicines.At present, business-like solid state laser optical maser wavelength is mainly at near-infrared and infrared band.Go for bluish-green laser output in solid state laser, mainly contain following three kinds of methods: (1) directly utilizes semiconductor material with wide forbidden band directly to make the semiconductor laser of bluish-green wave band; (2) utilize the nonlinear frequency transformation technology that Solid State Laser is carried out frequency multiplication; (3) switch technology realizes bluish-green laser output in the utilization in the crystal of mixing rare earth or glass.For the semiconductor laser diode (LD) of visible waveband, development blue, green glow LD needs expensive equipment and backing material, and the beam quality of LD is unsatisfactory simultaneously, is restricted in many applications; And, need nonlinear crystalline material to carry out frequency inverted by the frequency multiplication solid state laser of LD pumping, and though beam quality is fine, power output is also very high, system is complicated.In recent years, people utilize on the frequency in luminous and change the mechanism, and greatly develop to have blue green light output up-conversion luminescent material, and the pumping source that is adopted is generally the near-infrared high-power semiconductor laser.In addition, compare with crystal laser with rear-earth-doped glass, fiber laser has advantages such as volume is little, output wavelength is many, tunable range is wide.The fiber laser of conversion optical fiber fabrication also has advantage simple in structure, that efficient is high, cost is low in the utilization.
The blue green light fiber laser is to utilize the luminescence mechanism of changing on the rare earth ion, promptly adopts wavelength during the sample of long excitation light irradiation Doped Rare Earth ion, launches the light of wavelength less than excitation wavelength.The up-conversion luminescence mechanism of rare earth ion generally can be divided into excited state absorption, energy shifts and the photon avalanches process.At present, the rare earth ion that can obtain blue light output mainly contains Tm
3+And Pr
3+Two kinds, the rare earth ion that obtains green glow output mainly contains Er
3+Ion.In order to improve pump absorption efficient, often in rare earth ion, mix other sensitized ions altogether, as Yb
3+Ion.
Rear-earth-doped its working media of last conversion optical fiber laser of existing blue green light output is mainly with ZrF
3-BaF
2-LaF
3-AlF
3The fluoride glass of-NaF (ZBLAN) system is main.Why the fluoride glass system becomes the up-conversion luminescence host material of people's favor, be because have lower phonon energy, lower phonon energy can reduce the probability of glass radiationless relaxation in pumping process, improve the fluorescence lifetime of the middle metastable energy level of rare earth ion, thereby effectively improve the efficient of up-conversion luminescence.But chemical stability that fluoride glass is relatively poor and lower mechanical strength have been brought great difficulty for its practical application.
Summary of the invention
Technical problem to be solved by this invention provides and a kind ofly can reduce the resonant cavity internal loss, and is easy to adjust the last conversion optical fiber laser of the blue green light output of light path.
The present invention solves the problems of the technologies described above the technical scheme that is adopted: a kind of last conversion optical fiber laser of blue green light output, comprise pumping source, the input coupled lens, the output coupled lens, resonant cavity and rare earth ion doped optical fiber, described resonant cavity comprises input cavity sheet and output cavity sheet, this laser also comprises rail plate, described rail plate is provided with five dimension optical adjusting frames, four-dimensional optical adjusting frame and two-dimension optical adjustment rack, described input cavity sheet is pressed close to the input end face setting of described rare earth ion doped optical fiber, described output cavity sheet is pressed close to the output end face setting of described rare earth ion doped optical fiber, the both ends of the surface of described rare earth ion doped optical fiber are separately fixed on the described five dimension optical adjusting frames, described input coupled lens and described output coupled lens are fixed on the described four-dimensional optical adjusting frame, and described input cavity sheet and described output cavity sheet are fixed on the described two-dimension optical adjustment rack.
The matrix of materials of described rare earth ion doped optical fiber is the tellurate glass with low phonon energy.
The structure of described rare earth ion doped optical fiber is a doubly clad optical fiber.
The Doped Rare Earth ion is Tm in the fibre core of described rare earth ion doped optical fiber
3+, Pr
3+, Er
3+In any and Yb
3+Mixture.
Be coated with the anti-reflection film of 980nm wavelength on the surface of described input coupled lens, be coated with the anti-reflection film of 548nm wavelength on the surface of described output coupled lens.
Be coated with anti-reflectionly and to the Double-color film of the high reflection of 548nm wavelength to the 980nm wavelength on the surface of described input cavity sheet, being coated with 548nm wavelength transmitance on the surface of described output cavity sheet is 98% and to the Double-color film of the high reflection of 980nm wavelength.
Compared with prior art, the invention has the advantages that the input end face setting of the input cavity sheet being pressed close to rare earth ion doped optical fiber,, can effectively reduce the loss in the resonant cavity the output end face setting that the output cavity sheet is pressed close to rare earth ion doped optical fiber; The matrix of materials of rare earth ion doped optical fiber adopts the tellurate glass with low phonon energy, because tellurate glass material melting point height, end face damage threshold height, not easy damaged optical fiber during pumping source pumping tellurate glass optical fiber; The setting of rail plate, five dimension optical adjusting frame, four-dimensional optical adjusting frame and two-dimension optical adjustment racks, make by adjusting the position of rare earth ion doped optical fiber, input cavity sheet, output cavity sheet, input coupled lens and output coupled lens, realize the adjustment of light path easily.
Description of drawings
Fig. 1 is the structural representation of laser of the present invention.
Embodiment
Embodiment describes in further detail the present invention below in conjunction with accompanying drawing.
As shown in Figure 1, a kind of last conversion optical fiber laser of blue green light output, comprise pumping source 1, input coupled lens 2, output coupled lens 6, resonant cavity (not shown) and rare earth ion doped optical fiber 4, wherein, pumping source 1 is that a power output is that 5W, output wavelength are the semiconductor laser (LD) of 980nm; Be coated with the anti-reflection film of 980nm wavelength on the surface of input coupled lens 2, be coated with the anti-reflection film of 548nm wavelength on the surface of output coupled lens 6; Resonant cavity comprises input cavity sheet 3 and output cavity sheet 5, be coated with anti-reflectionly and to the Double-color film of the high reflection of 548nm wavelength to the 980nm wavelength on the surface of input cavity sheet 3, being coated with 548nm wavelength transmitance on the surface of output cavity sheet 5 is 98% and to the Double-color film of the high reflection of 980nm wavelength; The structure of rare earth ion doped optical fiber 4 is a doubly clad optical fiber, is doped with Er in the fibre core
3+And Yb
3+Rare earth ion, Er
3+And Yb
3+The doping content of rare earth ion is respectively 3000ppm and 20000ppm, and the diameter of fibre core is 50 μ m, and the inner cladding diameter is 150 μ m, and fiber lengths is 40cm.At this, doping Er
3+And Yb
3+Rare earth ion, output be green glow.If will export blue light, then can in fibre core, mix Tm altogether
3+And Yb
3+, or Pr
3+And Yb
3+In this specific embodiment, high reflection is meant that reflectivity is higher than more than 99.5%.
This laser also comprises rail plate 7, rail plate 7 is provided with five dimension optical adjusting frame (not shown)s, the four-dimensional optical adjusting frame (not shown) that pitching orientation up and down is adjustable and the two-dimension optical adjustment rack (not shown) of translation up and down, input cavity sheet 3 is pressed close to the input end face setting of rare earth ion doped optical fiber 4, output cavity sheet 5 is pressed close to the output end face setting of rare earth ion doped optical fiber 4, the both ends of the surface of rare earth ion doped optical fiber 4 are separately fixed on the five dimension optical adjusting frames, input coupled lens 2 and output coupled lens 6 are fixed on the four-dimensional optical adjusting frame, input cavity sheet 3 and output cavity sheet 5 are fixed on the two-dimension optical adjustment rack, and this structure is easy to adjust light path and realizes laser generation.Five dimension optical adjusting frames, four-dimensional optical adjusting frame and two-dimension optical adjustment rack all adopt prior art.
In this specific embodiment, the matrix of materials of rare earth ion doped optical fiber adopt have low phonon energy with TeO
2Composition is main tellurate glass, because tellurate glass material melting point height, end face damage threshold height, not easy damaged optical fiber during pumping source 1 pumping tellurate glass optical fiber.
The adjustment process of this laser is: by four-dimensional optical adjusting frame, utilize optics autocollimatic method will import coupled lens 2 and be transferred to the laser vertical sent with pumping source 1 and coaxial; Put into rare earth ion doped optical fiber 4, and the both ends of the surface of rare earth ion doped optical fiber 4 are fixed on the five dimension optical adjusting frames, regulate five dimension optical adjusting frames, the laser vertical that the input end face that makes rare earth ion doped optical fiber 4 and pumping source 1 send and coaxial, at this moment, inject laser, and increase the power of pumping source gradually, green laser or blue laser appear when reaching laser threshold, the output end face of regulating rare earth ion doped optical fiber 4 is coaxial with output coupled lens 6, can obtain parallel green or blue circle hot spot.