Window transmission curves

This page displays window transmission curves for several of the windows Lake Shore offers for our cryostats. Please consult with a sales engineer to determine which materials are right for your cryostat and experiment requirements.

Thank you to ISP Optics for providing curves for their uncoated windows.

Thank you to Tydex Optics for providing curves for their windows for THz use (shown at the bottom of the page).

Lake Shore — environment by JANIS

Amtir-1 (amorphous material)

AMTIR-1 Amorphous Material Transmission Curve

Window transmission curves provided by ISP Optics.

Download the AMTIR-1 Amorphous Material Transmission Curve Datasheet.

Barium Fluoride (BaF2)

Barium Fluoride BaF2 Transmission Curve

Window transmission curves provided by ISP Optics.

Download the Barium Fluoride BaF2 Transmission Curve Datasheet.

Caesium Iodide (CsI)

CaesiumIodide CsI Transmission Curve

Window transmission curves provided by ISP Optics.

Download the CaesiumIodide CsI Transmission Curve Datasheet.

Cadmium Telluride (CdTe)

Cadmium Telluride CdTe Transmission Curve

Window transmission curves provided by ISP Optics.

Download the Cadmium Telluride CdTe Transmission Curve Datasheet.

Calcium Fluoride (CaF2)

Calcium Fluoride CaF2 Transmission Curve

Window transmission curves provided by ISP Optics.

Download the Calcium Fluoride CaF2 Transmission Curve Datasheet.

Gallium Arsenide (GaAs)

Gallium Arsenide GaAs Transmission Curve

Window transmission curves provided by ISP Optics.

Download the Gallium Arsenide GaAs Transmission Curve Datasheet.

Fused Silica UV grade (SiO2)

Fused Silica UV Grade SiO2 Transmission Curve

Window transmission curves provided by ISP Optics.

Download the Fused Silica UV Grade SiO2 Transmission Curve Datasheet.

Fused Silica IR grade (SiO2)

Fused Silica IR Grade SiO2 Transmission Curve

Window transmission curves provided by ISP Optics.

Download the Fused Silica IR Grade SiO2 Transmission Curve Datasheet.

Quartz crystalline (SiO2)

Quartz SiO2 Transmission Curve

Window transmission curves provided by ISP Optics.

Download the Quartz SiO2 Transmission Curve Datasheet.

PLEASE NOTE: Crystal quartz windows are provided in random orientation by default. Z-cut crystal quartz is available by special request.

Magnesium Fluoride (MgF2)

Magnesium Fluoride MgF2 Transmission Curve

Window transmission curves provided by ISP Optics.

Download the Magnesium Fluoride MgF2 Transmission Curve Datasheet.

Potassium Bromide (KBr)

Potassium Bromide KBr Transmission Curve

Window transmission curves provided by ISP Optics.

Download the Potassium Bromide KBr Transmission Curve Datasheet.

Potassium Chloride (KCl)

Potassium Chloride KCl Transmission Curve

Window transmission curves provided by ISP Optics.

Download the Potassium Chloride KCl Transmission Curve Datasheet.

Sapphire (Al2O3)

Sapphire Al2O3 Transmission Curve

Window transmission curves provided by ISP Optics.

Download the Sapphire Al2O3 Transmission Curve Datasheet.

PLEASE NOTE: Sapphire windows are provided in random orientation by default. C-cut sapphire is available by special request.

Silicon (Si)

Silicon Si Transmission Curve

Window transmission curves provided by ISP Optics.

Download the Silicon Si Transmission Curve Datasheet.

Thallium-Bromoiodide (KRS-5)

Thallium Bromoiodide KRS-5 TlBr-TlI Transmission Curve

Window transmission curves provided by ISP Optics.

Download the Thallium Bromoiodide KRS-5 TlBr-TlI Transmission Curve Datasheet.

Zinc Selenide (ZnSe CVD)

Zinc Selenide Laser Grade ZnSe CVD Transmission Curve

Window transmission curves provided by ISP Optics.

Download the Zinc Selenide Laser Grade ZnSe CVD Transmission Curve Datasheet.

Zinc Sulfide (ZnS Cleartran)

Zinc Sulfide Cleartran(r) ZnS Transmission Curve

Window transmission curves provided by ISP Optics.

Download the Zinc Sulfide Cleartran(r) ZnS Transmission Curve Datasheet.

THz components

(From the Tydex website.)

Terahertz (THz) radiation is located in the spectral region ~0.1 to 10 THz (~3 mm to 30 μm, 3 cm-1 to 300 cm-1) between the microwave and mid-infrared range of the electromagnetic spectrum.

Below we introduce transmission spectra and other properties of materials put to use for THz optics production. Measurements in the THz region were made at ABB FTIR spectrometer Bomem DA3 and Bruker IFS 125HR (measure of inaccuracy is 2 to 3% below 100 µm and 4 to 5% over 100 µm). Measurements in the near-infrared range were made at Perkin Elmer “Lambda- 9” (measure of inaccuracy <0.5%).

As you can see, all organic materials like TPX, PE, and PP have uniform stable transmission about 80 to 90% starting from ~200 µm and up to 1000 µm. Surely they excellently transmit at larger wavelengths too.

Crystalline materials like silicon, quartz, and sapphire have lower transmission in THz range due to reflection losses.

Transmission spectra for THz window materials

1. Polymers

From the Tydex website:

Among the large variety of available polymers, there are some of excellent terahertz transparencies with relatively low reflectivity. The best materials in this sense are TPX (polymethylpentene), polyethylene (PE), and polypropylene (PP).

1.1 Polymethylpentene (TPX)

From the Tydex website:

TPX is the lightest of all known polymers. It is optically transparent in UV, visible, and THz ranges.

THz-Polymethylpentene  TPX THz Region Transmission Curve
Fig. 1 Transmission of TPX 2 mm thick sample. THz region.

THz-Polymethylpentene TPX NIR and MIR Region Transmission Curve

Fig. 2 Transmission of TPX 2 mm thick sample. NIR & MIR regions.

THz-Polymethylpentene TPX UV and VIS and NIR Ranges Transmission Curve

Fig. 3 Transmission of TPX 2 mm thick sample. UV & VIS & NIR ranges.

 

MaterialTPX
Available diameters, mmto 100
Diameter tolerance, mm±0.25
Thickness tolerance2% of thickness but not more than 0.1 mm
Surface quality, scr/dig80/50
Surface accuracy, λ at 30 µm1/3

THz-Polymethylpentene TPX Picarin HDPE Transmission Curve

Fig. 4 Transmission of 2 mm thick samples of TPX, Picarin, and HDPE.

1.2 Polyethylene (PE)

From the Tydex website:

THz-Polyethylene PE HDPE THz Region  Transmission Curve

Fig. 5 Transmission of 2 mm thick HDPE sample. THz region.

THz-Polyethylene PE HDPE NIR and MIR Region Tranmission Curve

Fig. 6 Transmission of 2 mm thick HDPE sample. NIR & MIR region. Unfortunately, HDPE transmission in the visible region is very poor.

THz-Polyethylene PE HDPE VIS and NIR Region Transmission Curve

Fig. 7 Transmission of 2 mm thick HDPE sample. VIS & NIR region.
MaterialHDPE
Available diameters, mmto 100
Dimensions tolerance, mm±0.25
Clear aperture, %≥90
Surface quality, scr/dig80/50

1.3 Polypropylene (PP)

From the Tydex website:

THz-Polypropylene PP THz Region Transmission Curve

Fig. 8 Transmission of polypropylene 2.0 mm thick sample. THz region.

THz-Polypropylene PP NIR and MIR Region Transmission Curve

Fig. 9 Transmission of polypropylene 2.0 mm thick sample. NIR & MIR region.

THz-Polypropylene PP VIS and NIR Region Transmission Curve

Fig. 10 Transmission of polypropylene 2.0 mm thick sample. VIS & NIR region.

2.1 Crystal quartz

From the Tydex website:

One of the best materials for wavelengths above 50 µm is z-cut crystal quartz. It is important that z-cut crystal quartz windows are transparent in the visible range allowing easy adjustment with HeNe laser, do not change the state of light polarization, and can be cooled down below the λ-point of liquid helium. PLEASE NOTE: Crystal quartz windows are provided in random orientation by default. Z-cut crystal quartz is available by special request.

THz-Crystal Quartz Tranmission Curve

Fig. 13 Transmission of crystal quartz 1.0 mm-thick.

Crystal quartz is a birefringent material; that should be taken into account if the polarization of radiation is of importance.

MaterialTHz grade crystal quartz
OrientationZ-cut*
Dimensions tolerance, mm±0.25
Clear aperture, %≥90
Parallelism, arc. min.5
Surface quality, scr/dig60/40

*Crystal quartz windows are provided in random orientation by default. Z-cut crystal quartz is available by special request.

2.2 Sapphire

From the Tydex website:

Sapphire like crystalline quartz is transparent in THz region as well as in visible one. As can be seen from the graph, spectra transmission doesn't depend on crystal orientation within measure of inaccuracy. PLEASE NOTE: Sapphire windows are provided in random orientation by default. C-cut sapphire is available by special request.

THz-Sapphire Transmission Curve

Fig. 14 Transmission of sapphire samples with different thickness. Samples of various crystallographic orientations were measured.