Filament Technology

State-of-the-Art Filament Technology

Helioworks has a broad capability in the design and manufacture (including coil winding) of steady state and pulsable sources utilizing Tungsten, NiCr, and Kanthal filaments. We have developed patented, state-of-the-art incandescent IR sources utilizing tungsten filaments for high temperature, stable, and long life operation.

If our standard models do not meet your needs, please let us know your requirements.

Tungsten Filament IR Sources

Tungsten filaments are used in most common incandescent light bulbs but these have glass or quartz envelopes that do not transmit well in the infrared. Tungsten achieves the highest temperature and power of any practical material and is therefore a valuable source of infrared emission in the near infrared (NIR). However, to make a source of intense infrared emission using tungsten, one must use another protective window. HelioWorks has chosen Sapphire because of its high transmission in the NIR. The uniqueness of our patented EP-series incandescent lamps is the integration of the sapphire window with the tungsten filament within a sealed metallic package.

Another innovation of these sources is an internal gold plated parabolic reflector. Gold has a very high reflectance in the near infrared. This reflectance is several percent greater than polished aluminum which is typically used in conventional infrared sources.

Tungsten filaments are provided in a variety of sizes to accommodate various frequency and modulation requirements. Operating temperatures up to 1900°K are standard with the EP-series source. Pulsable versions feature large temperature modulation at elevated frequency.

Nichrome (NiCr) Filament IR Sources

Nichrome (NiCr) filaments are made from ultra thin metallic strips. The metallic strips have a very high surface to volume ratio and thus a very short thermal time constant. They heat up and cool down or modulate very rapidly. The elements are typically attached in a series configuration to increase the overall resistance of the emitter (EF-series). This unique design avoids the problem of “current crowding” which causes uneven heating of the radiating elements often encountered with planar IR emitters. Window options include no window, Sapphire, Calcium Fluoride (CaF2) and Zinc Selenide (ZnSe).

Key Features:

  • NiCr filament with emissivity of 0.88
  • Uniform emitting area and temperature with no “current crowding” effect
  • NiCr filaments operate at peak temperature of 700°C (973°K)

Kanthal Filament IR Sources

Kanthal filaments are wire wound in the form of right cylindrical coils of various diameters and length. All of the Kanthal based lamps (EK-series) operate in steady state with constant low voltage DC input for long life.

Key Features:

  • Kanthal filament with emissivity of 0.7
  • Window options: no window, sapphire, Calcium Fluoride (CaF2), Zinc Selenide (ZnSe)
  • Internal gold plated parabolic reflector
  • Industry standard TO-3, TO-5, or TO-8 packages
  • Inert gas backfill