Passive mode-locking ultrashort pulse all-fiber laser with waveband of 2.0 microns

Abstract

The invention relates to a passive mode-locking ultrashort pulse all-fiber laser with a waveband of 2.0 microns and belongs to the field of a laser technology and nonlinear optics. The passive mode-locking ultrashort pulse all-fiber laser with the waveband of 2.0 microns mainly comprises a laser pumping source, a pumping combiner, thulium-doped or thulium-holmium-codoped rear earth doped fibers, a circulator, a saturable absorber, a laser beam splitter, an isolator, a fiber bragg grating, a polarization controller and the like. The thulium-doped or thulium-holmium-codoped rear earth doped fibers are used as a gain medium; the saturable absorber is used as a passive mode-locking device; and the output of an ultrashort laser pulse which is in the waveband of 2.0 microns and has high pulse energy is realized. Due to the adoption of the all-fiber structure design, the passive mode-locking ultrashort pulse all-fiber laser with the waveband of 2.0 microns has the advantages of simple structure, high environment stability and the like, and the industrialization application is easy to realize.

Description

technical field

[0001] The invention relates to a 2.0 micron band passive mode-locked ultrashort pulse all-fiber laser, which belongs to the field of laser technology and nonlinear optics. Background technique

[0002] Thulium-doped or thulium-holmium co-doped fiber lasers can emit laser light in the 2.0 micron band, and can also achieve wide tuning of the spectral range in the 1.7-2.1 micron band. In addition, laser output in other bands can also be achieved through up-conversion. Since the laser output in the 2.0 micron band is within the safe range of human eyes, and water molecules have strong mid-infrared absorption peaks, thulium-doped or thulium-holmium co-doped fiber lasers in the 2.0 micron band are widely used in eye safety, laser surgery, laser Radar, ultrafast optics and other fields have important application prospects. In addition, the 2.5-5.0 micron and 8.0-12.0 micron bands are two windows in atmospheric transmission. Lasers in this band are extremely import...

Examples

Embodiment 1

[0027] A 2.0 micron band passively mode-locked ultrashort pulse all-fiber laser adopts such as figure 1 The design of the annular chamber structure shown. It mainly includes: a multimode semiconductor laser with a central wavelength of 790nm and an output power of 6W as a laser pump source 1; a pump combiner 2 with a (2+1)x1 structure; a 10m-long thulium-doped double-clad single-mode fiber 3 As the gain medium, the thulium-doped double-clad single-mode fiber 3 has a core diameter of 6 μm and a cladding diameter of 125 μm; a three-port optical fiber circulator 4; a reflective semiconductor saturable absorber mirror with a modulation depth of 30% ( SESAM); a laser beam splitter 6 with a 1×2 structure and a beam splitting ratio of 30:70. Among them: the central wavelength is 790nm, the multimode semiconductor laser 1 with the output power of 6W is connected to the pumping input end of the (2+1)x1 pumping beam combiner 2; the common of (2+1)x1 pumping beam combiner 2 One end of ...

Embodiment 2

[0029] A 2.0 micron band passively mode-locked ultrashort pulse all-fiber laser adopts such as Figure 4 The design of the annular chamber structure shown. It mainly includes: a single-mode erbium-doped fiber laser with a center wavelength of 1550nm and an output power of 3W as a laser pump source 1; a 1550 / 2000nm wavelength division multiplexer (WDM) as a pump beam combiner 2; a 3m-long thulium-doped fiber laser The double-clad single-mode fiber 3 is used as the gain medium. The core diameter of the thulium-doped double-clad single-mode fiber 3 is 9 μm, and the cladding diameter is 125 μm; a polarization-independent isolator 7 with an isolation of 30 dB; a graphene with a transmission structure A saturable absorber 5; a laser beam splitter 6 with a 1×2 structure and a beam splitting ratio of 20:80. Among them: the single-mode erbium-doped fiber laser 1 with a center wavelength of 1550nm and an output power of 3W is connected to the pump input end of the wavelength division m...

Embodiment 3

[0031] A 2.0 micron band passively mode-locked ultrashort pulse all-fiber laser adopts such as Figure 5 The linear cavity structure design shown. It mainly includes: a single-mode erbium-doped fiber laser with a central wavelength of 1550nm and an output power of 3W as a laser pump source 1; a 1550 / 2000nm wavelength division multiplexer (WDM) as a pump optical beam combiner 2; a central wavelength of 2000nm, A fiber Bragg grating 8 with a 3dB spectral bandwidth of 2nm and a reflectivity of 90%; a 3m-long thulium-doped double-clad single-mode fiber 3 is used as the gain medium, and the core diameter of the thulium-doped double-clad single-mode fiber 3 is 9 μm. A layer diameter of 125 μm; a reflectively structured semiconductor saturable absorber mirror (SESAM) 5 with a modulation depth of 40%. Among them: a single-mode erbium-doped fiber laser with a center wavelength of 1550nm and an output power of 3W is connected to the pump input end of the wavelength division multiplexer...

technical field

[0001] The invention relates to a 2.0 micron band passive mode-locked ultrashort pulse all-fiber laser, which belongs to the field of laser technology and nonlinear optics. Background technique

[0002] Thulium-doped or thulium-holmium co-doped fiber lasers can emit laser light in the 2.0 micron band, and can also achieve wide tuning of the spectral range in the 1.7-2.1 micron band. In addition, laser output in other bands can also be achieved through up-conversion. Since the laser output in the 2.0 micron band is within the safe range of human eyes, and water molecules have strong mid-infrared absorption peaks, thulium-doped or thulium-holmium co-doped fiber lasers in the 2.0 micron band are widely used in eye safety, laser surgery, laser Radar, ultrafast optics and other fields have important application prospects. In addition, the 2.5-5.0 micron and 8.0-12.0 micron bands are two windows in atmospheric transmission. Lasers in this band are extremely import...

Examples

Embodiment 1

[0027] A 2.0 micron band passively mode-locked ultrashort pulse all-fiber laser adopts such as figure 1 The design of the annular chamber structure shown. It mainly includes: a multimode semiconductor laser with a central wavelength of 790nm and an output power of 6W as a laser pump source 1; a pump combiner 2 with a (2+1)x1 structure; a 10m-long thulium-doped double-clad single-mode fiber 3 As the gain medium, the thulium-doped double-clad single-mode fiber 3 has a core diameter of 6 μm and a cladding diameter of 125 μm; a three-port optical fiber circulator 4; a reflective semiconductor saturable absorber mirror with a modulation depth of 30% ( SESAM); a laser beam splitter 6 with a 1×2 structure and a beam splitting ratio of 30:70. Among them: the central wavelength is 790nm, the multimode semiconductor laser 1 with the output power of 6W is connected to the pumping input end of the (2+1)x1 pumping beam combiner 2; the common of (2+1)x1 pumping beam combiner 2 One end of ...

Embodiment 2

[0029] A 2.0 micron band passively mode-locked ultrashort pulse all-fiber laser adopts such as Figure 4 The design of the annular chamber structure shown. It mainly includes: a single-mode erbium-doped fiber laser with a center wavelength of 1550nm and an output power of 3W as a laser pump source 1; a 1550 / 2000nm wavelength division multiplexer (WDM) as a pump beam combiner 2; a 3m-long thulium-doped fiber laser The double-clad single-mode fiber 3 is used as the gain medium. The core diameter of the thulium-doped double-clad single-mode fiber 3 is 9 μm, and the cladding diameter is 125 μm; a polarization-independent isolator 7 with an isolation of 30 dB; a graphene with a transmission structure A saturable absorber 5; a laser beam splitter 6 with a 1×2 structure and a beam splitting ratio of 20:80. Among them: the single-mode erbium-doped fiber laser 1 with a center wavelength of 1550nm and an output power of 3W is connected to the pump input end of the wavelength division m...

Embodiment 3

[0031] A 2.0 micron band passively mode-locked ultrashort pulse all-fiber laser adopts such as Figure 5 The linear cavity structure design shown. It mainly includes: a single-mode erbium-doped fiber laser with a central wavelength of 1550nm and an output power of 3W as a laser pump source 1; a 1550 / 2000nm wavelength division multiplexer (WDM) as a pump optical beam combiner 2; a central wavelength of 2000nm, A fiber Bragg grating 8 with a 3dB spectral bandwidth of 2nm and a reflectivity of 90%; a 3m-long thulium-doped double-clad single-mode fiber 3 is used as the gain medium, and the core diameter of the thulium-doped double-clad single-mode fiber 3 is 9 μm. A layer diameter of 125 μm; a reflectively structured semiconductor saturable absorber mirror (SESAM) 5 with a modulation depth of 40%. Among them: a single-mode erbium-doped fiber laser with a center wavelength of 1550nm and an output power of 3W is connected to the pump input end of the wavelength division multiplexer...

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