JPH0274539A - Infrared light-transmitting glass fiber - Google Patents

Abstract

PURPOSE:To obtain the title continuous-form glass fiber with reduced loss at long wavelength zone by using an infrared transmitting materials which contains specific atomic percentages of Se, Te and I, shows light-transmitting properties in long wavelength area and is so stable that it does not crystallize, while it is spun into fibers. CONSTITUTION:Infrared transmitting chalcogenide glass fibers are provided, which is composed of Se, 20-70atm.%; Te, 10-40atm.%; and I, 20 to 48atm.%; where the total is 100atm.%. In other words, the glass parent material of the above-stated composition can give a glass of reduced loss at long wave-length and the glass is spun into infrared-transmitting glass fibers with loss reduced in long wavelength. The fibers are suitably used as a material for sensors and waveguide ways in industry to make light-transmitting windows of low loss in an area of 5-12/mum wavelength.

Description

[Detailed description of the invention] [Industrial field of application] Mizumoto type shows good infrared transmittance up to long wavelength range,
Especially in industry, as a material for sensors and optical waveguides.
The present invention relates to a glass material that can be used to create an infrared transparent fiber having a light transmission window with low loss in the wavelength range of 12 μm.

[Prior Art] Conventionally, chalcogenide glass containing a chalcogen element as a raw material has been considered promising as an infrared transmitting glass material. An example of chalcogenide glass is △s-8
and/or Se-based glass, Ge-8 and/or Se-based glass, Qc-AS-8e-Te-based glass fiber, etc.
Qe in the composition.

Materials containing As, S, Se, Te, etc. have been investigated. However, these infrared-transmissive glass fibers have the above-mentioned drawbacks, and at present they cannot provide low-loss light transmittance at wavelengths of 10 μm or more.

[Problem to be solved by the invention 1 Chalcogenide glass elements s, se, Te and G
In chalcogenide glass fibers containing e and AS as composition components, AS-3 or Se bonds, Ge-8
Alternatively, the optical transparency in a long wavelength range is limited due to polyphonic absorption of lattice vibration of Se bond. For example, Δs-3 glass fiber has a diameter of 6 μm or more, Qe-3e glass fiber has a diameter of 8 μm or more, Ge-Δ5-8e glass fiber has a diameter of 9 μm or more, and Qe-Δ5-8e-Te glass fiber has a diameter of 10 μm or more. 9 above in the wavelength range
Currently, optical loss is limited by polyphonic absorption based on the bonds between raw material elements, and it is difficult to provide an optical fiber with low loss in a longer wavelength range.

Therefore, the object of the present invention is to improve the optical transparency in the long wavelength region by J+
Moreover, the present invention provides a stable infrared transmitting material v1 that does not crystallize during fiber spinning, and provides a long glass fiber with low loss using the glass material r1.

[Means for Solving the Problems] In order to achieve the l-opening objective, the present invention has a composition ratio of Se of 20 to yoat, % and Te of 10 to 40 at, %.
This can be achieved by using a chalcogenide glass characterized in that 1 and 1 are 20 to 48 at%, and the total composition ratio of 81 is 100 at%.

Regarding the 3e-Te-1 chalcogenide glass mentioned here, J. Lucas said, ``Nisby Eye''
E” Volume 843, InfraRed Optical Materials and Fipers VJ (J, Luc
as et at, SPI [Vol, 8431nrr
areed optical materials an
d Fibers V (1987) P.

2), but no study has been made regarding a stable composition range that can withstand fiber spinning. The present invention provides a glass fiber with low loss in the long wavelength range by limiting the composition ratio to the above.

The infrared transmittance of chalcogenide glass is limited by lattice vibrations based on the bonds between raw material elements constituting the glass matrix. In a chalcogenide glass containing As and/or Ge as an element, v+1 element, the infrared transmittance at long wavelengths is determined by polyphonic absorption inherent in the glass based on, for example, As-8 or Se bonds, or Ge-8 or Se bonds. Therefore,
In order to reduce optical loss in the long wavelength range, it is necessary to shift the absorption due to lattice vibration inherent in glass to the long wavelength side.

The frequency (ν) of this lattice imaging is inversely proportional to the atoms m of the glass constituent elements, and therefore the wavelength of the lattice vibration (λ−C
/shi) is proportional to the atomic group of the glass constituent elements, and the larger the atomic weight of the glass constituent elements, the longer the wavelength will be shifted.

The raw material elements of the chalcogenide glass provided by the present invention are elements having a smaller atomic weight than the Se (atomic weight 1fi 78.96) element, such as S (atomic weight 32.06), Q
e(13i<childff172.59) andhi A S (
Because it does not contain any elements such as 7474, 92) and consists of chalcogenide element Te (atomic group 127.6) and halogen element 1 (Wt element 126.9), which has a large atomic group, it It becomes possible to shift phonon absorption to the longer wavelength side. Therefore, it is possible to create a glass with low loss in the long wavelength range. Further, 1.L: By spinning the above-mentioned glass, it is possible to create an infrared transmitting fiber with low loss in the long wavelength range.

In particular, in order to achieve the goal of lowering the loss at the carbon dioxide laser wavelength of 10.6 μm, we need to select elements with large atomic weights that shift polyphonic absorption toward long wavelengths to be the most stable vitrification region that can be spun. Contains a lot of 5e25-2.5T030
It is desirable to achieve 1+ within the composition range of ±2.5145±2.5.

In the stable vitrification region shown in FIG. 1, a glass having the composition shown in FIG. 2 was synthesized, fiber was spun, and the state and loss value of the glass and fiber were examined. Mainly Te5oI45, Se content is 27. Even if it exceeds sat%, the loss value is at least higher than 22.5at%. Furthermore, if the Te content decreases, the glass will crystallize during glass synthesis or the fiber will devitrify during spinning. On the contrary, it was found that as it increases, the loss value increases due to scattering. It has also been found that as the I content increases, the glass becomes more likely to crystallize, while as it decreases, the loss value increases. Therefore, the glass composition that exhibits the lowest loss at the carbon dioxide laser wavelength is S
e2. 5825-2. centered on Te5oI45 composition.
Limited within the range of 5T030±2.5145±2.5+.

[Function] The glass composition constituting the infrared transmitting optical fiber material of the present invention has polyphonic absorption based on lattice vibration on the long wavelength side, and can transmit infrared rays in the long wavelength range with low loss. Become.

[Example] The present invention will be explained in detail below.

99.99999% Se, tk degree 99.99999%
Anhydrous quartz glass ampoule (inner diameter 1
0m+φ, wall thickness 2.5m+, length 150im),
After filling under argon gas atmosphere, vacuum degree 10'To
Vacuum sealed with rr. The quartz glass ampoule containing this glass raw material was heated and melted in a rocking furnace at 700° C. for 40 hours, and then taken out from the furnace and rapidly cooled at room temperature to obtain a glass rod.

In order to evaluate this glass, scanning calorimetry was performed at a scanning temperature of 10° C./min to check for the presence or absence of crystallization peaks. FIG. 1 shows 5 (3-T) determined in this example.

Thermal analysis of -1-based chalcogenide glass showed a stable vitrification region in which no crystallization peak was observed.

The vitrification region in which no crystallization peak is observed exists in a wide range, and the degree of freedom in composition selection is wide.
This shows that the 1-series chalcogebuit glass is a stable glass system. Further, since no crystallization peak is observed in the glass within this vitrification region, it is shown that it is possible to create a good optical fiber without causing crystallization during fiber spinning.

As an example, a glass within the above-mentioned stable vitrification region was created, and the resulting glass lot with a length of 60rnM and a diameter of 10mφ was heated to a pressure of 0.59/crj from a quartz glass nozzle.
We created optical fibers by spinning them and investigated their loss. Table 1 summarizes the minimum loss value of the glass fiber obtained, the wavelength at that time, and the loss value at a carbon dioxide laser wavelength of 10.6 μm. In particular, 5e within the desirable range mentioned above.
It can be seen that the glass fiber with a composition of 25Te3oI45 has the lowest loss.

From this example, by selecting a composition within the stable vitrification range, it is possible to create an infrared transmitting bamboo optical fiber with low obsolescence at the desired wavelength. FIG. 3 shows the wavelength-loss characteristics of a glass fiber made of 5e25Te3o [45 dark blue, which has the least loss.

The loss value was 0.9 dB/m at 10.6 μm.

[Effects of the Invention] As described above, the composition of the 5e-Te-1 chalcogenide glass shown in FIG. Can be created.

Furthermore, it is a light-transmitting material that satisfactorily transmits infrared rays in the long wavelength range. In addition, since it is possible to create a fiber with low loss at the carbon dioxide laser wavelength of 10.6 μm, it has the advantage of being usable as a laser light waveguide and as an infrared transmitting glass material for sensors that use infrared rays and optical communications. have.

[Brief explanation of the drawing]

Figure 1 shows the stable vitrification region of 5e-Te-1 chalcogenide glass, Figure 2 shows 5e25Te3oI
Figure 3 shows the glass composition centered on the 45 composition and the loss value at a carbon dioxide laser wavelength of 106 μm.
It is a figure which shows the wavelength-loss characteristic of the glass fiber of 3oI45 composition.

Claims (1)

[Claims] 1. The glass composition includes 20 to 70 at. %, T
e is 10 to 40 at. % and I are 20 to 48 at. %, and the total composition ratio is 100 at. % infrared transparent chalcogenide glass fiber. 2 The glass composition is Se_2_5_±_2_. _5Te_
3_0_±_2_. _5I_4_5_±_2_. The infrared transmitting chalcogenide glass fiber according to claim 1, which is _5.