From mid-IR to
millimetre-wave.
THz windows, lenses, polarizers and filters on HRFZ silicon, TPX, HDPE and quartz — plus the far-IR FTIR accessories that sit on the same benches. Frequency belongs on the RFQ.
Optics where glass is opaque.
Below ~3 THz most IR crystals go dark. We quote THz windows, lenses, polarizers and filters on the materials that still transmit — high-resistivity silicon, TPX, HDPE, PTFE and z-cut quartz — plus the FTIR accessories that sit on the long-wave edge of the same benches.
- Useful band0.1 – 10 THz (3 mm – 30 µm)
- Workhorse windowHRFZ-Si · ρ > 10 kΩ·cm
- Polymer opticsTPX (PMP) · HDPE · PTFE
- FTIR overlapPE · CsI · KRS-5 · Si
Why not ZnSe?
ZnSe is excellent to ~14–16 µm and then drops. A 1 THz (300 µm) beam does not care about your 10.6 µm AR. Tell us frequency in THz or cm−1, not “IR.”
- 1 THz300 µm · 33.3 cm−1
- 3 THz100 µm · 100 cm−1
- 10 THz30 µm · 333 cm−1
Windows
Plane and wedged THz windows. HRFZ silicon for vacuum and cryostat ports; TPX/HDPE where weight and index matching matter; z-cut quartz when you also need a visible alignment path.
- Ø typical12.7 – 100 mm
- Wedge0° or 0.5–2° (etalon)
Lenses
TPX aspheres and silicon spherical/aspheric lenses for collimation and focusing of photoconductive antennas and multiplier sources.
- EFL25 – 150 mm typical
- Index (Si)n ≈ 3.42 (THz)
Polarizers & filters
Free-standing and substrate wire-grid polarizers. Low-pass and band-pass filters for source harmonics. Attenuators and etalons to print.
- ExtinctionQuoted per THz
- FilterLow-pass · band-pass
FTIR long-wave accessories
The same benches that run 4000–400 cm−1 often need PE windows, far-IR beamsplitters and ATR elements when the scan is pushed toward 100 cm−1.
- WindowsPE · CsI · KRS-5
- NoteWedge & etalon
Beamsplitters & OAPs
Silicon and mylar beamsplitters; off-axis parabolas for THz collimation without chromatic focus shift.
- OAPEFL and off-axis angle
- SplitTo print
Detectors (RFQ / sourced)
Golay cells and pyroelectric heads are quoted as sourced instruments when the RFQ is for a detection chain, not only the optic. Send NEP, chopping frequency and window material.
- Quote asSourced, not stock
- WindowMust match the band
Frequency first.
- Center frequency (THz) or wavenumber (cm−1) and bandwidth
- Vacuum, atmosphere or cryostat — condensation kills some polymers
- Clear aperture, thickness, wedge
- Polarization requirement, if any
- Source type (PCA, QCL multiplier, FTIR globar)
Put THz on the print.
Frequency, aperture and environment are enough to start a window or lens quote.