Intermediate infrared thulium-holmium co-doped sesquioxide laser single-crystal optical fiber, and preparation method and application thereof

Abstract

The invention specifically relates to an intermediate infrared thulium-holmium co-doped sesquioxide laser single-crystal optical fiber, and a preparation method and application thereof, belonging to the technical field of laser materials. According to the intermediate infrared thulium-holmium co-doped sesquioxide laser single-crystal optical fiber provided by the invention, intermediate infrared laser in a waveband of 3.2-4.3 microns can be generated through transition between two excited state energy levels (5I5 to 5I6) of Ho<3+>; co-doping Tm<3+> has the synergistic effects of sensitizationand deactivation on the active ion Ho<3+>, can be used as both a sensitizing ion for the Ho<3+> and a deactivating ion for Ho<3+>, and allows the service life of the laser lower energy level 5I6 of Ho<3+> to be effectively shortened and the service life of the laser upper energy level 5I5 to be free of obvious changes, so a laser threshold value is favorably reduced, and the output efficiency andpower of laser are improved.

Description

technical field [0001] The invention relates to the technical field of laser materials, in particular to a mid-infrared thulium-holmium co-doped sesquioxide laser single crystal fiber and its preparation method and application. Background technique [0002] Mid-infrared lasers in the 3.2-4.3 μm band have broad application prospects in the fields of gas environment monitoring, spectroscopy, ocean detection, laser medical treatment, atmospheric remote sensing, lidar and infrared photoelectric countermeasures. At present, there are mainly the following methods to achieve mid-infrared laser output in the 3.2-4.3 μm band: 1) nonlinear optical frequency conversion technology, this method requires a high-coherence pump source and a suitable infrared nonlinear optical crystal, and realizes laser The output device system has a complex structure and low cost performance, which limits its application range and field; 2) Semiconductor quantum cascade laser technology, which produces low...

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Problems solved by technology

However, based on Ho 3+ The 3.2-4.3 μm mid-infrared laser output achieved by doping fluoride and other laser materials is still difficult to be widely used, mainly due to the following reasons: 1) The mechanical properties of fluoride are poor, the threshold of anti-photodamage is low, the growth conditions are harsh and Difficulty in obtaining high-quality crystals, etc.; 2) Ho 3+ The absorption band does not match the laser wavelength of the currently developed semiconductor laser (LD), it is difficult to use LD to pump directly, and its absorption is weak near 890nm, Cr 3+ :LiSrAlF 6 Or Ti:Sapphire laser pumping efficiency is low, which leads to low laser efficiency, and makes the system complex and poor in stability; 3)Ho 3+ laser upper level 5 I 5 The lifetime is much lower than the lower energy level 5 I 6 The lifetime of the laser is not conducive to the inversion of the number of particles between the upper and lower energy levels of the laser. It not only has a high threshold but also has an important impact on the laser efficiency.

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