Infrared Glass Manufacturing

In-House Production of Synthetic Infrared Glasses, with different optical properties

Chalcogenide Materials for NIR, SWIR, MWIR and LWIR Uses

US Manufacturing Capacity of 10 Metric Tons a Year. Suitable for Diamond Turning and Precision Molding

Overview

With a long history of experience in Chalcogenide Glass production, LightPath produces a variety of different Chalcogenide glasses in its Orlando, Florida facility.

All of LightPath’s Black Diamond™ 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 diamond turned into lenses, conventionally polished, or molded into final form using our precision glass molding technology.

We produce our BD6 and BD2 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.

In November of 2021 LightPath received from the US Naval Research Laboratories (NRL) an exclusive usage license for additional Chalcogenide glasses developed by NRL’s scientists. LightPath is currently in the process of transitioning these materials into production. For more details, please contact us.

Properties

-3dB Transmission window

SWIR (1-3μm)

MWIR (3-5μm)

LWIR (8-12μm)

Physical Properties

Glass

λ short (μm)

λ long (μm)

Index dn/dT (ppm/°C) V(1-3) Index dn/dT (ppm/°C) V(3-5) Index dn/dT (ppm/°C) V(8-12) Density (g/cm3) Tg (°C) CTE (ppm/°C) Thermal Power (1/°C)
BDNL4 0.78 17.50 2.66 -17.30 17 2.64 -18.60 186 2.63 -18.30 233 4.47 201 30.20 -41.37
BDNL5 0.74 17.20 2.49 9.61 19 2.47 7.62 184 2.46 6.33 126 4.42 192 26 -21.67
BDNL6 1.43 18.20 3.22 202 3.17 169 107 3.15 160 257 5.23 191 18.30 56.04
BDNL7 0.57 12.70 2.40 -4.38 24 2.38 -7.34 159 2.357 -8.11 47 3.17 201 25.30 -31.27
BDNL8 0.79 18.90 2.68 2.97 16 2.66 1.20 184 2.64 -0.40 186 4.51 193 25.70 -25.94
BDNL9 0.61 12.80 2.43 -3.64 23 2.41 -3.83 160 2.38 -5.94 51 3.28 197 25.10 -29.37
BDNL10 0.74 17.50 2.54 27.20 18 2.52 22.60 191 2.51 21 135 4.44 191 27 -13.10
BDNL16 0.74 13 2.59 21 18 2.57 14 157 2.55 12 78 3.89 182 24 -16.29
BDNL103 2.73 65 16 2.71 61 170 2.70 58 167 4.54 314 14 20.10
BD6 0.83 17.50 2.81 14.10 2.79 169.20 2.781 30.50 159.40 4.63 185 22.50 -5.38
BD2 0.93 16 2.63 2.621 173.70 2.60 61.10 109 4.66 285 14 24.13

Advantages

Chalcogenide Glasses (LightPath’s family of Black DiamondTM materials), are synthetically produced Amorphous materials, with advantages optical characteristics for use in the infrared spectrum.

Being amorphous materials, optics can be fabricated from them using precision glass molding techniques, allowing for significant cost savings in the fabrication process. Additionally, being synthetic materials, we can fine tune their properties, leading to different Thermo-Optic coefficient (dn/dT), changes in the dispersion curve, refractive indexes and more.

  • The main advantages of Chalcogenides include:
  • Full IR spectrum transmission
  • High Refractive Index
  • Soft but durable
  • Lower density than Germanium (=Lighter weight)
  • Not susceptible to thermal runaway
  • Moldable – finished optics can be fabricated using precision glass molding
  • Large diameter. Can be fabricated in different sizes

Glass Manufacturing Process

Image Gallery

BD6 Slice

BD6 Boule

BDNL4 Lenses

BDNL6 Boule

BDNL4 Boule

Chalcogenide Glass Rocking Furnace

Chalcogenide Glass Boules

BD6 Boules

Chalcogenide Boules From Above

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