Made in the USA
Negative dn/dT
Based on NRL’s NRL-4 Glass
Overview
Based on the research work done at Naval Research Laboratories (NRL), LightPath has commercialized this unique, multispectral infrared glass under an exclusive license from NRL.
All of LightPath’s BlackDiamond™ Chalcogenide glasses are produced in boules of 120mm diameter, and can be further expanded using our proprietary molding technology, to larger diameters, as needed. Our Black Diamond™ materials are designed specifically to have the same refractive index whether polished by diamond turning into lenses, conventionally polished, or molded into final form using our precision glass molding technology.
We produce our BlackDiamond™ glasses in quantities of up to 10 metric tons annually, and can further expand our production capacity. Like many other manufacturing processes at LightPath, most of our critical production equipment for these processes is either designed and built by LightPath engineering team, or by modifying existing commercial equipment. This allows us to achieve unique properties, such as materials that have the same refractive index whether molded or polished by Diamond Turning.
Specifications
| Wavelength (μm) | Refractive Index (@20°C) |
|---|---|
|
1 |
2.754 |
|
2 |
2.667 |
|
4 |
2.647 |
|
6 |
2.643 |
|
8 |
2.639 |
|
10 |
2.636 |
|
12 |
2.632 |
|
14 |
2.628 |
| @2 μm | @4 μm | @10 μm | |
|---|---|---|---|
|
Dn/dT [10–6/K] @22°C |
-9.7 |
-14.3 |
-16.3 |
| Material Properties | |
|---|---|
|
Density |
4.50 g/cm3 |
|
Thermal Expansion (20 – 100°C) |
25.2 (ppm/°C) |
|
Thermal Conductivity |
0.17 (W/m*K) |
|
Transition Temperature |
205°C |
|
Hardness (Vickers) |
151 HV |
|
Young’s Modulus |
14.2 GPa |
| Wavelength | Transmission (%/mm) | Extinction Coefficient (cm-1) |
|---|---|---|
|
1.0 |
99.29 |
0.00057 |
|
1.5 |
99.62 |
0.00046 |
|
2.0 |
99.68 |
0.00051 |
|
2.5 |
99.71 |
0.00058 |
|
3.0 |
99.44 |
0.00133 |
|
3.5 |
99.73 |
0.00074 |
|
4.0 |
99.76 |
0.00077 |
|
4.5 |
99.74 |
0.00091 |
|
5.0 |
99.75 |
0.00101 |
|
5.5 |
99.73 |
0.00118 |
|
6.0 |
99.72 |
0.00135 |
|
6.5 |
99.67 |
0.00172 |
|
7.0 |
99.76 |
0.00134 |
|
7.5 |
99.72 |
0.00169 |
|
8.0 |
98.95 |
0.00670 |
|
8.5 |
99.72 |
0.00187 |
|
9.0 |
99.76 |
0.00170 |
|
9.5 |
99.74 |
0.00198 |
|
10.0 |
99.64 |
0.00287 |
|
10.5 |
99.28 |
0.00608 |
|
11.0 |
99.01 |
0.00867 |
|
11.5 |
98.08 |
0.01775 |
|
12.0 |
91.59 |
0.08391 |
|
12.5 |
76.70 |
0.26351 |
|
13.0 |
73.92 |
0.31314 |
|
13.5 |
86.70 |
0.15332 |
|
14.0 |
93.69 |
0.07250 |
|
14.5 |
96.00 |
0.04711 |
|
15.0 |
95.81 |
0.05112 |
|
15.5 |
96.61 |
0.04249 |
Manufacturing Readiness
