TPX / HDPE Terahertz Plano Convex Lens | SIMTRUM Photonics Store

There are two types of metamaterials with good terahertz transmittance mainly include high-molecular-weight materials and high-resistance silicon, Among them, the refractive index of high-resistance silicon (HRFZ-Si) is high. This material is more suitable for making lens. 

Among the high-resolution materials, polymethylpentene (TPX) has the best transmission performance in terahertz, but for optical-grade TPX materials due to High shrinkage ratio and low yield during injection molding result in high prices. Therefor terahertz window materials are generally using polytetrafluoroethylene (Teflon), high-density polyethylene (HDPE), TPX, high-resistance silicon, these materials are the main materials for terahertz lenses. 

There are many types of terahertz lenses. Commonly seen are mainly plano-convex non-spherical lenses, cone lens (used to produce Bessel beam), spiral phase plate, cylindrical lens, multi-hemispherical lens, Fresnel lens to reduce the thickness, etc. Terahertz lens was use in terahertz spectrometers and terahertx imagers for collimation and focus, or reverse use.

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HDPE is a light elastic crystalline material. It can be heated to 110°C or cooled to -45 ~ -120°C. PE has good dielectric properties, corrosion resistance, and radiation resistance. At 23°C, the density is 0.91-0.925 g/cm3, the tensile flow limit is 8-13 MPa, the elastic modulus is 118-350 MPa, and the refractive index is about 1.54 in a wide spectral range. Usually, HDPE also comes as a component material. In addition to thick lenses and windows, thin HDPE can also be used as THz polarizers.

It should be noted that the THz transmission of HDPE is independent of temperature, thus allowing the use of HDPE windows in cryostats. Its temperature coefficient of refractive index is 6.2 × 10-4 K-1 (range 8-120 K).

The frequency range covers terahertz to far-infrared 7um-3mm (100GHz-43THz), with high transmittance in the terahertz frequency range, relatively stable physical and chemical properties, highly polarized, and fast response.

Transmission of 2mm-thick HDPE sample, THz eegion.

Standard Specificatoin Choice

Customized size and focal length is available please Contact Us 

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