Dielectric Constant: 1.96 at 520 GHz
|Design Frequency||500 GHz, n=1.4|
|Surface Irregularity||10 μm, corresponding to λ/20 at 1.5 THz|
|Diameter Tolerance||+0.00/-0.20 mm|
|Surface Quality||60-40 Scratch-Dig|
|Spherical Surface Power*||0.0025λ|
|Clear Aperture||>85% of diameter|
*Much like surface flatness for flat optics, surface power is a measure of the deviation between the surface of the curved optic and a calibrated reference gauge, typically for a 633 nm source, unless otherwise stated. This specification is also commonly referred to as surface fit.
Teflon® Plano-Convex Lenses
As part of our continuing effort to make new technologies available to our customers, Thorlabs offers components for use in the THz range. Our intention is to continually broaden the THz product offerings in the future.
We provide plastic plano-convex lenses made with Polytetrafluoroethylene (Virgin White PTFE, Teflon®), which has a low dielectric constant of approximately 1.96 @ 520 GHz and an index of refraction of 1.4. The low dielectric constant of PTFE ensures that the insertion loss is reasonably low. PTFE is usable for frequencies up to ~2 THz.
The Terahertz (THz) range can be expressed as the frequency range of 300 GHz to 10 THz or the wavelength range of 30 μm to 1 mm. Until recently, the THz range was a relatively unused part of the electromagnetic spectrum; however, in recent years the THz band has been gaining popularity in applications such as spectroscopy, astronomy, remote sensing, and in security (THz imaging). The THz band is situated between microwaves and optics on the electromagnetic spectrum. This location influences the mixture of microwave and optical technologies used in the THz band.