Please note: Due to maintenance the shop will be unavailable on Tuesday, May 24, from 06:00 AM until 08:00 AM (CEST)

IRG 24

IRG 24

IRG 24 has excellent transmission in the SWIR, MWIR, & LWIR and has the lowest dn/dT of the IR series glasses.

Physical properties such as low dn/dT and low dispersion enable optical engineers to design color corrected optical systems without thermal defocusing.

Furthermore, IRG 24 can be processed by conventional grinding and polishing, single point diamond turning, or molding to support low to high volume component level fabrication.

IR characteristics
Composition Ge10As40Se50
Density 4.47 g/cm3
Thermal Expansion (20°C-100°C) 20.0·10-6/K
Transition Temperature 225°C
Thermal Change dn/dT (at 1 µm) 45.9·10-6/K
Thermal Change dn/dT (at 5 µm) 21.1·10-6/K
Thermal Change dn/dT (at 10 µm) 20.3·10-6/K
Refractive Index (n at 10 µm) 2.6090
Surface quality 60/40 polished both sides
Surface flatness ≤ 5 waves P-V per surface at 632.8nm
Edge Worked Saftety bevel
Glass type
Article DIA
T
Weight
Wavelength
[µm]
Transmission
(10 mm)
Transmission
(2 mm)
Extinction
[cm-1]
0.8 52.2 87.8 0.650
1.0 91.4 98.2 0.090
1.5 96.7 99.3 0.034
2.0 97.5 99.5 0.026
2.5 97.5 99.5 0.025
3.0 98.3 99.7 0.017
3.5 98.5 99.7 0.015
4.0 98.7 99.7 0.013
4.5 96.3 99.3 0.037
5.0 97.0 99.4 0.031
5.5 99.5 99.9 0.005
6.0 99.7 99.9 0.003
6.5 99.7 99.9 0.003
7.0 99.7 99.9 0.003
7.5 99.2 99.8 0.008
8.0 95.2 99.0 0.049
Wavelength
[µm]
Transmission
(10 mm)
Transmission
(2 mm)
Extinction
[cm-1]
8.5 98.5 99.7 0.015
9.0 98.8 99.8 0.012
9.5 98.7 99.7 0.013
10.0 98.8 99.8 0.012
10.5 97.8 99.6 0.022
11.0 93.7 98.7 0.065
11.5 78.0 95.2 0.248
12.0 40.2 83.4 0.910
12.5 15.8 69.2 1.844
13.0 16.9 70.1 1.779
13.5 43.0 84.4 0.845
14.0 65.2 91.8 0.428
14.5 70.3 93.2 0.353
15.0 64.3 91.5 0.442
15.5 49.9 87.0 0.696
Constants of Dispersion Formulas
B1 2.8965
B2 2.9567
B3 0.9461
C1 0.0000
C2 0.1620
C3 1,939.1000
D0 1.80·10-5
E0 2.10·10-5
λTK 1.67·10-3
Calculation Formula: Refractive index as a function of wavelength and temperature
Wavelength
[µm]
Refractive Index
(@ 22 °C)
Δn abs/ΔT [10–6/K]
22 °C
0.8 2.8028 0.0
0.9 2.7555 0.0
1.0 2.7555 46.0
1.5 2.7249 31.3
2.0 2.6612 26.3
3.0 2.6274 22.9
4.0 2.6222 21.7
5.0 2.6192 21.1
6.0 2.6170 20.8
7.0 2.6151 20.6
8.0 2.6132 20.5
9.0 2.6111 20.4
10.0 2.6090 20.3
11.0 2.6066 20.2
12.0 2.6040 20.2
Wavelength
[µm]
Thermal Change
[dn/dt]
1 µm 45.9·10-6/K
5 µm 21.1·10-6/K
10 µm 20.3·10-6/K