JPH06219774A - Eu-doped laser glass - Google Patents

Abstract

PURPOSE:To provide a red color-luminescent laser glass high in luminescent intensity. CONSTITUTION:The objective laser glass comprises 5-20cat% of Eu<3+>. Another version of the objective laser glass contains Eu<3+> as luminescent ion and Sm<3+> as sensitizer; specifically, having the following composition: 5-20cat% of Eu<3+>, 0.5-3cat% of Sm<3+>, 50-65cat% of PO2.5, 1-10cat% of BO1.5, 1-10cat% of SiO2 and 1-15cat% of BaO, and, if needed, containing AlO1.5, R2O (R is Na, Li or K) and/or RO (R is Mg, Zn, Ca or Sr). Irradiation of either of the above laser glass with the rays from a Xe lamp emits laser beams 0.61mum in wavelength.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a doped Eu ³⁺ for a sensitizer of laser glass and Sm ³⁺ capable of generating light of red doped with Eu ³⁺ (about 0.61 .mu.m) The present invention relates to a laser glass capable of generating red (about 0.61 μm) light. The laser glass of the present invention is
It is useful as a red light source, a red laser light source, a glass display material, and the like.

[0002]

2. Description of the Related Art Conventionally, a crystal capable of continuously emitting red light having a wavelength of 0.66 to 0.67 μm with an Er ion (Er ³⁺ ) as an emission center by excitation with an infrared laser having a wavelength of about 0.8 μm or Glass is known (Applied Physics Letters Vol. 54, page 2301 (1
989)). According to this report, Er ions absorb red light in two stages and excite it to a higher energy state,
It emits light having a shorter wavelength than the excitation light by transitioning from the high energy state to light emission, which is called up-conversion phenomenon. In addition, as a material having excellent up-conversion efficiency, there is a report on a fluoride glass containing ZrF ₄ and AlF ₃ containing Er ions as main components (Academic Society of Applied Physics 91 Autumn Meeting, 10aPB19).

[0003]

The material that causes the up-conversion phenomenon is infrared light (0.8 μm or 0.98 μm).
By irradiating m), red light (0.66 μm) can be emitted only at the irradiated portion, and it can be used as a display material. However, when used as a display material, it is necessary that the emission intensity of red light is high. Therefore, for example, by increasing the concentration of Er ions in the material, a material having a large emission intensity has been realized. Furthermore, if the emission intensity of red light increases,
It is also possible to use this material itself as a light emitting source of a red laser.

As an upconversion glass,
Using 0.8 μm LD and Tm ³⁺ as a sensitizer, Er ³⁺
A red-emitting laser glass with a wavelength of 0,67 μm is known (the 39th Annual Meeting of the Applied Physics Society of Japan 30).
PD-14). However, the red emission intensity obtained here was not sufficient for some applications.

By the way, as shown in the energy level diagram of FIG. 1, Eu ³⁺ (europium) has a large energy gap of 16,000 cm ^{−1 in} emission from ⁵ D ₀ to ⁷ F ₂ , and ⁵ D _0. There is no energy level between 1 and ⁷ F ₆ . This is, ⁵ D ₀ of Eu ³⁺ - In the ⁷ F ₂ emission, hardly nonradiative transitions occur, showing that the quantum efficiency of luminescence is high. However, a laser glass containing Eu ³⁺ as a luminescent ion and having a high emission intensity has not been studied so far. In fact, in order to obtain a red color with high emission intensity, it is necessary to obtain a high concentration of Eu ³⁺ , but a base glass capable of containing a high concentration of Eu ³⁺ has not been known.

Further, although an LD (laser diode) is used as a light source for the laser using the up-conversion or non-linear crystal, there is a limit to the emission wavelength of the LD which can be practically used. On the other hand, the Xe flash lamp is in practical use although it has a broad emission wavelength. Therefore, there is also a need to provide a red laser glass that can use a practical Xe flash lamp as a light source.

Therefore, the object of the present invention is to increase the concentration of Eu ^3+.
The present invention is to provide a laser glass containing Eu ³⁺ , which emits red light with high emission intensity and which can also use a Xe flash lamp as a light source.

[0008]

The present inventors have completed the present invention by finding that boric acid-based glass has a high solubility of Eu ³⁺ and hardly causes concentration quenching.

The present invention relates to a laser glass containing Eu ³⁺ in the range of 5 to 20 cat% (cation percentage) (hereinafter referred to as the first laser glass of the present invention).

Further, the present invention relates to a laser glass containing Eu ³⁺ as a light emitting ion and Sm ³⁺ as a sensitizer (hereinafter referred to as a second laser glass of the present invention).

Further, according to the present invention, Eu ³⁺ is added in an amount of 5 to 20 cat.
%, Sm ³⁺ 0.5 to ³ cat%, PO _2.5 50 to 6
5 cat%, BO _1.5 1-10 cat%, SiO ₂ 1-
The present invention relates to a laser glass containing 10 cat% and 1 to 15 cat% of BaO (hereinafter referred to as the third laser glass of the present invention).

In any of the laser glasses of the present invention, when Eu ³⁺ is contained in an amount of 5 to 20 cat% as shown in FIG. 2, the emission of 0.61 μm becomes high. Eu ³⁺ content is
In the case of any of the first to third laser glasses of the present invention, it is preferably 10 to 18 cat%.

Further, the second and third laser glasses of the present invention contain Sm ³⁺ (samarium) as a sensitizer.
As shown in FIG. 2, by containing Sm ³⁺ ,
The emission of 0.61 μm is higher. As shown in FIG. 3, the added amount of Sm ³⁺ is preferably in the range of 0.5 to 3 cat% from the viewpoint of obtaining higher emission intensity. Sm ³⁺ is 400 nm ( ⁶ H _5/2 to ⁵ P _5/2 ).
It has a strong absorption at 5 nm and a strong emission at 560 nm and 595 nm, but it is considered that this emission energy transits to ⁵ D _{0 of} Eu ³⁺ to enhance the emission at 0.61 μm.

As the base glass of the third laser glass of the present invention, PO _2.5 is 50 to 65 cat%, BO _1.5 is 1 to 10 cat%, SiO ₂ is 1 to 10 cat% and BaO.
_2.5- BO _1.5- SiO containing 1 to 15 cat% of
_2- BaO type glass is used. Boric acid type glass is E
It is preferable because the solubility of u ³⁺ is high and the concentration quenching hardly occurs. If PO _2.5 is less than 50 cat%, it tends to devitrify, and if it exceeds 65 cat%, vitrification becomes difficult. When BO _1.5 is less than 1 cat%, the solubility of Yb ions is not sufficiently improved. When BO _1.5 exceeds 10 cat%, the glass becomes unstable and devitrification easily occurs. SiO ₂ is 1
If it is less than cat%, the glass becomes unstable and devitrification tends to occur, and if it exceeds 10 cat%, SiO ₂ becomes difficult to melt, and a high melting temperature is required. If BaO is less than 1 cat%, vitrification does not occur, and if it exceeds 15 cat%, the glass becomes unstable and devitrification easily occurs.

FIG. 4 shows the vitrification region of the P ₂ O ₅ —BaO—Eu ₂ O ₃ system (expressed in mol%). From Figure 4 Eu ₂ O
₃ is found to have the broadest vitrification region when BaO in the phosphate glass is from about 10 mole%.

The above PO _2.5 -BO _1.5 -SiO ₂ -Ba
In addition to the above essential components, the O-based glass may contain 1.5 cat% or less of AlO _1.5 in order to improve the stability of the glass. Also, instead of BaO, BaO
By substituting 10 cat% or less of R ₂ O (R is lithium, sodium or potassium) and / or 5 cat% or less of RO (R is magnesium, zinc, calcium or strontium) with glass. It can also be used as a component system to improve stability and prevent devitrification. However, the total of BaO, R ₂ O, and RO is 1 to 15 c.
At%

The base glass of the first and second laser glasses of the present invention is 5 to 20 cat%, preferably 10 to 18 c.
There is no particular limitation as long as it can contain at% Eu ³⁺ . However, it is preferable to use a boric acid-based glass from the viewpoint that the solubility of Eu ³⁺ is high and the concentration quenching hardly occurs. Examples of the boric acid-based glass include P mentioned above.
O _2.5 -BO _1.5 -SiO ₂ -BaO-based glass may be mentioned.

Each of the first to third laser glasses of the present invention can generate a laser beam of 0.61 μm by irradiating the Xe flash lamp having a wavelength of 400 to 600 nm.

[0019]

EXAMPLES The present invention will be described in more detail below with reference to examples. Example 1 PO _2.5 is 59.4 cat%, BO _1.5 is 6.4 cat%,
SiO ₂ 5.0 cat%, AlO _1.5 0.7 cat%,
NaO _0.5 6.8 cat%, CaO 2.0 cat%, Ba
O is 2.1 cat%, EuO _1.5 is 16.4 cat%, Sm
A glass having a composition of O _1.5 of 1.1 cat% was prepared using a high-purity raw material, melted at 1400 ° C. using a platinum crucible, homogenized by stirring, and then cooled. Annealing is performed at a glass transition temperature (Tg) for 30 minutes, and then T
The laser glass of the present invention was obtained by slowly cooling at g-50 ° C and then cooling at a rate at which the glass did not break.

The results of the optical properties and laser performance of the obtained glass are shown in Table 1. Furthermore, the emission spectrum (solid line) when this glass was pumped by a Xe lamp (5 mW) is shown in FIG. In addition, in FIG.
The emission spectrum (dashed line) when d-doped phosphate glass is pumped under the same conditions is also shown.

[0021]

[Table 1]

Example 2 A laser glass having the same composition as in Example 1 except that Sm was not included was obtained in the same manner as in Example 1. The emission spectrum (broken line) when the obtained glass was pumped with a Xe lamp in the same manner as in Example 1 is shown in FIG. The solid line in FIG. 6 is the emission spectrum of the glass of Example 1.

Example 3 A glass was prepared in the same manner as in Example 1 ^except that Sm ³⁺ in the glass of Example 1 was kept constant at 1 mol% and the amount of Eu ^{3+ was changed to} the amount shown in FIG. The emission intensity of 0.61 μm obtained by irradiating the obtained glass with a Xe lamp in the same manner as in Example 1 is shown as □ in FIG.

Example 4 A glass in which the amount of Eu ³⁺ in the glass of Example 2 containing no Sm ³⁺ was varied to the amount shown in FIG. 2 was obtained in the same manner as in Example 2. The emission intensity of 0.61 μm obtained by irradiating the obtained glass with a Xe lamp in the same manner as in Example 2 is shown as ◯ in FIG.

Example 5 A glass was prepared in the same manner as in Example 1 ^except that Eu ³⁺ in the glass of Example 1 was kept constant at 15 mol% and the amount of Sm ³⁺ was varied to the amount shown in FIG. The emission intensity of 0.61 μm obtained by irradiating the obtained glass with a Xe lamp in the same manner as in Example 1 is shown in FIG.

[0026]

According to the present invention, P is used as the base glass.
A laser glass capable of containing a higher concentration of Eu ³⁺ can be obtained by using O _2.5 -BO _1.5 -SiO ₂ -BaO system glass. Further, this laser glass shows a high emission intensity at 0.61 μm by using a Xe flash lamp as a light source.

[Brief description of drawings]

FIG. 1 is an energy level diagram of Eu ³⁺ .

FIG. 2 shows the Eu ³⁺ content and the emission intensity of 0.61 μm in the laser glass of the present invention (◯ does not contain a sensitizer, □ contains 1 ct% of the sensitizer (Sm ³⁺ )). Show the relationship.

FIG. 3 shows the laser glass (Eu ³⁺ of 15 cat of the present invention).
Shows the relationship between the emission intensity of the content and 0.61μm of Sm ³⁺ in% inclusive).

FIG. 4 shows a vitrification region of a P ₂ O ₅ —BaO—Eu ₂ O ₃ system (expressed in mol%).

[5] The emission spectrum of the laser glass of Example 1 (Eu ³⁺ 15 mol%, including Sm ³⁺ 1 mol%) (solid line)
3 shows emission spectra (broken line) of Nd-doped phosphate glass.

6 the emission spectrum (broken line) and the laser glass (Eu ³⁺ Example 1 15 mol% of the laser glass of Example 2 (a Eu ³⁺ containing 15 mol%), including Sm ³⁺ 1 mol% ) Shows the emission spectrum (solid line).

Claims (4)

[Claims] 1. A laser glass containing 5 to 20 cat% (cation percentage) of Eu ³⁺ . 2. Eu ³⁺ as a luminescent ion, and S
A laser glass containing m ³⁺ as a sensitizer. 3. Eu ³⁺ of ₅ to 20 cat%, Sm ³⁺ of 0.5 to ³ cat%, PO _2.5 of 50 to 65 cat%, B
Laser glass containing 1 to 10 cat% of O _1.5 , 1 to 10 cat% of SiO ₂ and 1 to 15 cat% of BaO. 4. A light having a wavelength of 400 to 600 nm is used.
A method of irradiating the laser glass according to any one of 1 to 3 to generate red laser light.