Thulium doped lead fluoride crystal and preparation method thereof

Abstract

The invention relates to a thulium doped lead fluoride crystal. The molecular formula of the crystal is TmxPbF2+3x, wherein x is the dosage concentration of Tm3+ and is 0.1-10mol percent. A melt method is used for the growth of the crystal and comprises the following steps of: (1) selecting the value of x, and weighing raw materials by a stoichiometric ratio according to the molecular formula TmxPbF2+3x, wherein initial raw materials for the crystal growth comprise TmF3 and PbF2, and x is 0.1-10mol percent; (2) sufficiently and uniformly mixing the raw materials weighed by the ratio, drying in vacuum and pressing into blocks; and putting the blocks into a graphite crucible or a platinum crucible by using a PbF2 crystal as a seed crystal with a growth atmosphere of argon or CF4 gas. The crystal has the advantages of long fluorescence lifetime of 10ms and larger absorption and emission cross section and is expected to be applied to lasers within a wave band of 2mum of all-solid laser diode pumping.

Description

technical field

[0001] The invention relates to a laser crystal, in particular to a thulium-doped lead fluoride crystal and a preparation method thereof. Background technique

[0002] Due to the characteristics of atmospheric transmission and safety to human eyes, 2μm band laser is considered to be an ideal light source for medical and human eye safety detection systems, including medical surgery, laser ranging, laser difference instrument, coherent Doppler wind radar Wait. Since the 1960s, people have begun to study luminescent materials and lasers in the 2μm band, and have carried out in-depth research on how to improve the luminous efficiency and output power of 2μm band lasers. Especially in the 1970s, after the advent of high-power semiconductor lasers, more and more people paid more and more attention to the research on obtaining high-efficiency, high-output, and miniaturized 2μm-band lasers based on laser diodes as pump sources.

[0003] Thulium ions have an absorpt...

Examples

Embodiment 1

[0015] Embodiment 1: temperature gradient method grows Tm 0.01 PbF 2.03 the crystal

[0016] The high-purity raw material TmF 3 and PbF 2 According to molecular formula Tm 0.01 PbF 2.03 The molar ratio is for the ingredients to be fully mixed evenly, dehydrated at 150°C for 14 hours, and the charging container is polytetrafluoroethylene. Take it out and press it into a block, put it into a graphite crucible, the growth atmosphere is argon, cover the top of the crucible, raise the temperature at 50°C / hour to 920°C and keep it for 10 hours, then grow the crystal at a cooling rate of 4°C / hour, and the growth is over Then cool down to room temperature at a cooling rate of 20°C / hour.

Embodiment 2

[0017] Embodiment 2: Temperature gradient method grows Tm 0.05 PbF 2.15 the crystal

[0018] In this embodiment, the high-purity raw material TmF 3 and PbF 2 According to molecular formula Tm 0.05 PbF 2.15 For proportioning, the raw materials were dehydrated at 120°C for 16 hours and then put into a graphite crucible, and PbF was placed at the bottom of the crucible 2 The crystal is used as the seed crystal, and the growth atmosphere is CF 4 Protective gas, cover the top of the crucible, increase the temperature at 40°C / hour to 940°C for 8 hours, then grow crystals at a rate of 3°C / hour, and cool to room temperature at a rate of 30°C / hour after growth.

Embodiment 3

[0019] Embodiment 3: temperature gradient method grows Tm 0.1 PbF 2.3 the crystal

[0020] In this embodiment, the high-purity raw material TmF 3 and PbF 2 According to molecular formula Tm 0.1 PbF 2.3 For proportioning, the raw materials are dehydrated at 120°C for 12 hours and then put into a graphite crucible, and PbF is placed at the bottom of the crucible 2 The crystal is used as a seed crystal, the growth atmosphere is argon, the top of the crucible is covered, the temperature is raised to 960°C at a rate of 45°C / hour for 8 hours, and the crystal is grown at a temperature of 4°C / hour. The cooling rate is to cool to room temperature.

technical field

[0001] The invention relates to a laser crystal, in particular to a thulium-doped lead fluoride crystal and a preparation method thereof. Background technique

[0002] Due to the characteristics of atmospheric transmission and safety to human eyes, 2μm band laser is considered to be an ideal light source for medical and human eye safety detection systems, including medical surgery, laser ranging, laser difference instrument, coherent Doppler wind radar Wait. Since the 1960s, people have begun to study luminescent materials and lasers in the 2μm band, and have carried out in-depth research on how to improve the luminous efficiency and output power of 2μm band lasers. Especially in the 1970s, after the advent of high-power semiconductor lasers, more and more people paid more and more attention to the research on obtaining high-efficiency, high-output, and miniaturized 2μm-band lasers based on laser diodes as pump sources.

[0003] Thulium ions have an absorpt...

Examples

Embodiment 1

[0015] Embodiment 1: temperature gradient method grows Tm 0.01 PbF 2.03 the crystal

[0016] The high-purity raw material TmF 3 and PbF 2 According to molecular formula Tm 0.01 PbF 2.03 The molar ratio is for the ingredients to be fully mixed evenly, dehydrated at 150°C for 14 hours, and the charging container is polytetrafluoroethylene. Take it out and press it into a block, put it into a graphite crucible, the growth atmosphere is argon, cover the top of the crucible, raise the temperature at 50°C / hour to 920°C and keep it for 10 hours, then grow the crystal at a cooling rate of 4°C / hour, and the growth is over Then cool down to room temperature at a cooling rate of 20°C / hour.

Embodiment 2

[0017] Embodiment 2: Temperature gradient method grows Tm 0.05 PbF 2.15 the crystal

[0018] In this embodiment, the high-purity raw material TmF 3 and PbF 2 According to molecular formula Tm 0.05 PbF 2.15 For proportioning, the raw materials were dehydrated at 120°C for 16 hours and then put into a graphite crucible, and PbF was placed at the bottom of the crucible 2 The crystal is used as the seed crystal, and the growth atmosphere is CF 4 Protective gas, cover the top of the crucible, increase the temperature at 40°C / hour to 940°C for 8 hours, then grow crystals at a rate of 3°C / hour, and cool to room temperature at a rate of 30°C / hour after growth.

Embodiment 3

[0019] Embodiment 3: temperature gradient method grows Tm 0.1 PbF 2.3 the crystal

[0020] In this embodiment, the high-purity raw material TmF 3 and PbF 2 According to molecular formula Tm 0.1 PbF 2.3 For proportioning, the raw materials are dehydrated at 120°C for 12 hours and then put into a graphite crucible, and PbF is placed at the bottom of the crucible 2 The crystal is used as a seed crystal, the growth atmosphere is argon, the top of the crucible is covered, the temperature is raised to 960°C at a rate of 45°C / hour for 8 hours, and the crystal is grown at a temperature of 4°C / hour. The cooling rate is to cool to room temperature.

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