EN
EN
TPX is the lightest‑weight polymer known. It is transparent in the ultraviolet, visible and THz bands, so a He‑Ne laser can be used for beam collimation. The refractive index of this polymer is approximately 1.46 and exhibits little dependence on wavelength：
λ, µm | n |
0.633 | 1.463 |
24 | 1.4568 |
60 | 1.4559 |
300 | 1.46 |
667 | 1.46 |
1000 | 1.4650 |
3191 | 1.466 |
TPX exhibits very low transmission loss for millimeter‑waves. It possesses excellent heat resistance and is resistant to corrosion by a number of commercial chemicals.
Fig. 7 Transmission of TPX 2 mm-thick sample. THz region.
Fig. 8 Transmission of TPX 2 mm-thick sample. NIR&MIR regions.
Fig. 9 Transmission of TPX 2 mm-thick sample. UV&VIS&NIR ranges.
Main Properties of TPX：
Density, g/cm3 | 0.83 |
Tensile Strength | 4100 psi ~28.3 MPa |
Tensile Modulus | 280000 psi ~1930.5 MPa |
Elongation at Break, % | 10 |
Flexural Strength | 6100 psi ~42.1 MPa |
Flexural Modulus | 210000 psi ~1447.8 MPa |
Heat‑distortion temperature, °C | 100 |
Melting Temperature, °F/°C | 464/240 |
Water Absorption (ASTM-D 1228), % | <0.01 |
Water Vapor Permeability (thk 25 µm, 40C, 90%RH), g/m2*24h | 110 |
Gas Permeability y (thk 100 µm), cm3/m2*d*MPa | 120000 |
| Modulus of Rupture | 6000 psi~42.1 MPa |
TPX is a rigid solid‑state material that can be machined into various optical components, such as lenses and optical windows. Moreover, TPX is commonly employed as an output window in CO2‑laser‑pumped molecular laser systems. It is transparent across the entire THz band and capable of reflecting 10 μm pump light. TPX windows can also serve as "cold" windows inside cryostats. This is because the transmittance of TPX in the THz range is temperature‑independent, with a temperature coefficient of refractive index of 3.0*10-4 K-1 (for the range 8-120 K).
Fig. 10 Temperature dependence of refractive index.(***)
Compared with other materials used in the THz band, TPX exhibits superior properties. For instance, it serves as an excellent alternative to Picarin (Tsurupica) lenses. In addition, the TPX material supplied by Yichi Optoelectronics is more cost‑effective and more readily available than Picarin.
Fig. 11 Transmittance of 2 mm thick samples of TPX, PICARIN, HDPE and COC.
TPX windows can be used in vacuum applications down to a pressure of 10-9mm Hg.
