Click on the bars in the graph above to view the transmission plot for each optical material.
Thorlabs offers a wide variety of optical substrates that are ideal for use in various applications. The graph to the right compares the transmission ranges of some of the most common substrates we offer. This page details optical properties for these substrates, as well as the substrates used in our aspheric and achromatic lenses. To quickly navigate through these substrates, use the Table of Contents listed below or click on the tabs above.
For more information about the properties listed throughout this page, please see the Tutorial tab above. If you have questions about a substrate not described on this page, please contact Tech Support.
Table of Contents
This tab details the key crystalline, optical, physical, and thermal properties provided for the substrates featured on the rest of the tabs on this page. Please contact Tech Support if you have any further questions concerning these properties.
Table of Contents
Optical Properties
Index of Refraction
Index of refraction, n, is an optical property that describes how light propagates through a material. It is defined as
where c is the speed of light in a vacuum, and v is the speed of light through the material. The index of refraction of a material varies with both temperature and wavelength. The change of index of refraction with temperature is discussed in more detail in the Thermal Properties section below. The change in index of refraction with wavelength is known as dispersion and can be clearly seen in the graph to the right, which shows the variation in n for NBK7.
Attenuation Coefficient
The attenuation coefficient, α, is a material property that characterizes the degree of transparency of a medium. The intensity transmitted through a material is described by the BeerLambert law:
where I is the transmitted intensity, I_{0} is the incident intensity, and l is the thickness of the material. Losses described by the attenuation coefficient include both scattering and absorption by the material. Like index of refraction, the attenuation coefficient of a material varies with wavelength.
Sellmeier Equation
The Sellmeier equation is used to characterize the dispersion of light with respect to wavelength and is written in the form
where λ is wavelength in μm and B_{1} , B_{2} , B_{3} , C_{1} , C_{2} , and C_{3} are constants unique to the material being tested. The Sellmeier equation used to plot NBK7's index of refraction as a function of wavelength can be seen by clicking on the hyperlink in the footnote under the graph.
Abbe Number
Also known as the Vnumber, the Abbe number is an optical property that quantifies a material's dispersion, or variation in refractive index with respect to wavelength. It is defined by the equation
where V_{d} is the Abbe number, and n_{d} , n_{F} , and n_{C} are the refractive indexes of the material at 587.6 nm, 486.1 nm, and 656.3 nm, respectively. A high Abbe number is indicative of low dispersion whereas a low Abbe number indicates high dispersion.
Fresnel Reflectance and Transmittance
The Fresnel equations describe the reflection and transmission of light at an interface between two materials with different indices of refraction. These equations provide reflectance and transmittance values, which give the ratio of the reflected and transmitted light intensity, respectively, to the incident intensity. This can be written as
where R is the reflectance, T is the transmittance, I_{0} is the incident intensity, I_{r} is the reflected intensity, and I_{t} is the transmitted intensity. The Fresnel values given on this page are for normal incidence.
Physical Properties
Figure 1. Knoop Hardness Test
Knoop Hardness
Knoop hardness (HK) is a measure of a material's mechanical hardness and is most commonly given for brittle materials. Knoop hardness is tested by pressing a pyramidal diamondshaped indenter into a material sample and analyzing the resulting indentation in the material. The process is shown in the animation denoted as Figure 1 to the right. The Knoop Hardness is then calculated using
where HK is the Knoop hardness, K is a constant related to the indenter's geometry, P is the test load, and L is the longest diagonal length of the diamondshaped indentation.
Moduli: Young, Shear, and Bulk
Young's modulus, shear modulus, and bulk modulus are all measures of how a material deforms, or strains, under different stresses. Stress is the term used to describe the amount of force applied to a sectional area of a sample. Stress is mathematically calculated using the following equation:
where σ is stress and F is the force applied on the crosssectional area, A, of a sample. The term strain is used to describe the deformation of a sample as a result of a stress and is mathematically calculated using
where ε is strain, Δx is the change in size of a sample, and x is the original size of a sample.
Young's modulus, shear modulus, and bulk modulus are useful in quantifying the stiffness of materials. A stiffer material has higher moduli than a more flexible material.
Figure 2. Measurement of Young's Modulus
Young's Modulus
Young's modulus (E ), also known as elastic modulus, describes how a material deforms under a normal, or tensile, stress. To measure Young's modulus, a material is either pulled or compressed along its length, and the resulting change in length is measured. The animation in Figure 2 demonstrates one method of measuring Young's modulus. Mathematically, Young's modulus is calculated by dividing a sample's normal stress over its normal strain. In Figure 2 and in the equation below, E is Young's modulus, L is the original length of the sample, ΔL is the change in the length of the sample, and F is the force applied normal to the face of the sample with surface area, A.
Figure 3. Measurement of Shear Modulus
Shear Modulus
Shear modulus (G ) is the measure of how a sample deforms when it is sheared (i.e., when a force is applied parallel to one surface of the sample and an opposing force is applied to the opposite face, as shown in Figure 3). Mathematically, shear modulus is calculated by dividing a sample's shear stress by its shear strain. Shear stress and strain are demonstrated in the Figure 3 animation. Within the animation and in the following equation, G is the shear modulus, h is the height of the test sample, Δx is the change in shape due to the shear force, F , applied to the sample, and A is the surface area of the face to which the force is applied.
Figure 4. Measurement of Bulk Modulus
Bulk Modulus
Bulk modulus (K ) describes a material's volumetric stiffness when exposed to increased uniform pressure. When a material is exposed to high, uniform, external pressure, it tends to shrink. Bulk modulus is the measure of how much a material resists this shrinking. Mathematically, bulk modulus is calculated by dividing a sample's bulk stress by its bulk strain. In the Figure 4 animation and the equation below, K is the bulk modulus, V represents the original volume of the sample, and V′ is the volume of a sample after it is exposed to change in uniform pressure, ΔP.
Figure 5. Measurement of Poisson's Ratio
Poisson's Ratio
Poisson's ratio, ν (nu), is a measure of how much a material contracts in the perpendicular direction due to stretching, or conversely, how much a material expands in the direction perpendicular to the applied force due to its compression. Imagine stretching a rubber band and watching the band become thinner; as you continue to stretch it farther, the thinness also increases. Poisson's ratio can also be measured by compressing a material and measuring how much thicker it gets, as shown in the Figure 5 animation. Mathematically, Poisson's ratio is defined as the negative change in transverse strain divided by the change in axial strain. In Figure 5 and the equation below, ε_{trans} is transverse strain (i.e., the strain perpendicular to the applied force, F) and ε_{axial} is axial strain (i.e., the strain parallel to the applied force). dε_{axial} and dε_{trans} are the changes in strain on the sample due to an applied force.
Relationship between Poisson's Ratio and the Young's, Shear, and Bulk Moduli
In isotropic materials, there is a linear relationship between Poisson's ratio, Young's modulus, shear modulus, and bulk modulus. This makes it possible to calculate any unknown moduli of certain materials using only two known values. Isotropic materials have identical physical properties in every orientation. In other words, their properties do not vary as the axis along which the force is applied varies. Many optical glasses, such as NBK7 or NSF11, are isotropic and thus have moduli values calculated from the equations
where E is Young's modulus, G is shear modulus, K is bulk modulus, and ν is Poisson's ratio. These relationships are not true for anisotropic materials. Most crystalline materials, such as Thorlabs' fluoride optics, are anisotropic, and hence, each modulus must be measured separately. Moduli that were calculated rather than measured are noted in the specification table for every applicable substrate.
Thermal Properties
Coefficient of Thermal Expansion
The coefficient of thermal expansion (CTE) describes a material’s tendency to expand or contract with a change in temperature. A positive CTE would describe a material that expands with increases in temperature, and a negative CTE describes a material that contracts with increases in temperature. Specifically, the coefficient of linear thermal expansion (a_{L} ) is the numerical description of how much the length of a material changes with temperature and can be expressed as
where a_{L} is the coefficient of linear thermal expansion, L is the original length of the sample, dL is the change in length of the sample, and dT is the change in temperature.
Change in Index of Refraction with Temperature
The index of refraction of a material is not only dependent on the wavelength of light passing through it; it is also dependent on the temperature, as shown in the graph to the right. This change in index of refraction with temperature is also known as the thermooptic coefficient and is commonly written as dn/dT. Because the thermooptic coefficient varies both with temperature range and wavelength, a standard temperature range and test wavelength are selected when reporting this specification for a material.
Crystalline Properties
Parallel versus Perpendicular
Crystalline material data is often given for both the parallel and perpendicular axes of the crystal to ensure accuracy. The crystalline structure of some materials results in a difference between the properties along the optical axis and those along the perpendicular axis. The parallel, or extraordinary, axis is the axis along which transmitted light will suffer no birefringence. It is parallel to the optical axis of the crystal. The perpendicular, or ordinary, axis is perpendicular to the optical axis.
AlphaBBO Specifications 
Index of Refraction^{a} 

Index of Refraction at dLine (587.6 nm)^{a} 
n_{e} = 1.533 n_{o }= 1.673 
Sellmeier Equation, Extraordinary^{a} 

Sellmeier Equation, Ordinary^{a} 

Abbe Number (V_{d}), Extraordinary 
56.18 
Abbe Number (V_{d}), Ordinary 
52.23 
Transmission Range 
190 nm  3.5 µm 
Fresnel Reflectance and Transmittance, Extraordinary (Calculated) 

Fresnel Reflectance and Transmittance, Ordinary (Calculated) 

Density 
3.85 g/cm^{3} 
Knoop Hardness 
 
Young's Modulus 
39 GPa 
Shear Modulus 
12.3 GPa 
Bulk Modulus^{b} 
 
Poisson's Ratio 
0.58 
Coefficient of Thermal Expansion 
36 x 10^{6} /°C (Parallel) 4 x 10^{6} /°C (Perpendicular) 
Heat Capacity 
0.49 J/(g*K) 
Melting Point 
1095°C 
Change in Index of Refraction with Temperature 
9.3 x 10^{6} /°C (Parallel) 16.6 x 10^{6} /°C (Perpendicular) 
Click to Enlarge
Click
Here for Raw Data
This data was gathered through a GLB5 GlanLaser Polarizer of thickness
8.2 mm and is indicitive of the material's properties..
AlphaBBO (αBBO, αBaB_{2}O_{4}) is a negative uniaxial crystal, which is the high temperature form of βBBO, and exhibits many of the same physical and optical properties. AlphaBBO’s high birefringent structure makes it a useful substrate in the fabrication of polarization optics. Since αBBO is a soft crystal that is easily damaged, all of our αBBO polarizers are offered in metal housings. With convenient threadings and adapters, these housings can easily be mounted into our optomechanical products. AlphaBBO has a transmission range from 190 nm to 3.5 µm. It has an ordinary refractive index of 1.673 and an extraordinary refractive index of 1.533 at 587.6 nm.
Click on the images below or open the table to the right to see Thorlabs’ complete selection of optics made from αBBO.
Barium Fluoride Specifications 
Index of Refraction^{a} 

Index of Refraction at Nd:YAG (1.064 µm)^{a} 
1.468 
Sellmeier Equation^{a} 

Abbe Number (V_{d}) 
81.78 
Transmission Range 
200 nm  11 µm 
Fresnel Reflectance and Transmittance (Calculated) 

Density 
4.893 g/cm^{3} 
Knoop Hardness 
82 kg/mm^{2} 
Young's Modulus 
53.07 GPa 
Shear Modulus 
25.4 GPa 
Bulk Modulus 
56.4 GPa 
Poisson's Ratio 
0.343 
Coefficient of Thermal Expansion 
18.4 x 10^{6} /°C 
Heat Capacity 
0.41 J/(g*K) 
Melting Point 
1368 °C 
Change in Index of Refraction with Temperature (+20/+40°C @ 1060 nm) 
15.2 x 10^{6} /°C 
Barium Fluoride (BaF_{2}) is transparent from the UV to the IR (200 nm  11 µm) and has an index of refraction of 1.468 at 1.064 µm. Barium fluoride's properties are similar to those of calcium fluoride, but it is more resistant to highenergy radiation. It is, however, less resistant to water damage. Pronounced degradation of the BaF_{2} substrate occurs at 500 °C when exposed to water, but in dry environments, it can be used in applications requiring exposure to temperatures up to 800 °C.
When handling optics, one should always wear gloves. This is especially true when working with barium fluoride as it is a hazardous material. For your safety, please wear gloves whenever handling BaF_{2} and thoroughly wash your hands afterwards. Click here to download a pdf of the MSDS for BaF_{2}.
Click on the images below or open the table to the right to see Thorlabs’ complete selection of optics made from BaF_{2}.
Calcite Specifications 
Index of Refraction^{a} 

Index of Refraction at Nd:Yag (1.064 µm)^{a} 
n_{e} = 1.480 n_{o }= 1.642 
Sellmeier Equation, Extraordinary^{a} 

Sellmeier Equation, Ordinary^{a} 

Abbe Number (V_{d}), Extraordinary 
79.17 
Abbe Number (V_{d}), Oridinary 
49.91 
Transmission Range^{b} 
300 nm  2.3 μm 
Fresnel Reflectance and Transmittance, Extraordinary (Calculated) 

Fresnel Reflectance and Transmittance, Ordinary (Calculated) 

Density 
2.71 g/cm^{3} 
Knoop Hardness 
155 kg/mm^{2} 
Young's Modulus 
88.19 GPa (Parallel) 72.35 GPa (Perpendicular) 
Shear Modulus 
35 GPa 
Bulk Modulus 
129.53 GPa 
Poisson's Ratio 
0.85 
Coefficient of Thermal Expansion (@ 0°C) 
25 x 10^{6} /°C (Parallel) 5.8 x 10^{6} /°C (Perpendicular) 
Heat Capacity 
0.852 J/(g*K) 
Melting Point 
825°C 
Change in Index of Refraction with Temperature (@ 500 nm) 
3 x 10^{6} /°C (Parallel) 13 x 10^{6} /°C (Perpendicular) 
Calcite (CaCO_{3}), or Iceland Spar, is a useful crystalline substrate most commonly used in polarization optics. A calcite polarizer can be designed as either a polarization splitter/combiner or as a polarizer element that removes the angled, orthogonally polarized component of a beam. Since calcite is a soft crystal that is easily damaged, almost all of our calcite polarizers are offered in metal housings. With convenient threadings and adapters, these housings can easily be mounted into our optomechanical products. The transmission data above was taken through an uncoated GlanLaser calcite polarizer. Calcite has a transmission range from 300 nm to 2.3 μm. It has an ordinary refractive index of 1.642 and an extraordinary refractive index of 1.480 at 1.064 µm. It is not recommended to use these polarizers for input beams with wavelengths greater than 2.3 µm, as calcite has different absorption coefficients for the ordinary and extrarodinary rays that diverge past this point.
Click on the images below or open the table to the right to see Thorlabs’ complete selection of optics made from calcite.
Calcium Fluoride Specifications 
Index of Refraction^{a} 

Index of Refraction at Nd:YAG (1.064 µm)^{a} 
1.428 
Sellmeier Equation^{a} 

Abbe Number (V_{d}) 
95.31 
Transmission Range 
180 nm  8.0 µm 
Fresnel Reflectance and Transmittance (Calculated) 

Density 
3.18 g/cm^{3} 
Knoop Hardness 
158.3 kg/mm^{2} 
Young's Modulus 
75.8 GPa 
Shear Modulus 
33.77 GPa 
Bulk Modulus 
82.71 GPa 
Poisson's Ratio 
0.26 
Coefficient of Thermal Expansion 
18.85 x 10^{6} /°C 
Heat Capacity 
0.854 J/(g*K) 
Melting Point 
1418 °C 
Change in Index of Refraction with Temperature (+20/+40°C @ 1060 nm) 
10.6 x 10^{6} /°C 
Calcium Fluoride (CaF_{2}) is transparent from the UV to the IR (180 nm  8.0 µm). It has a refractive index of 1.428 at 1.064 µm and is mechanically and environmentally stable. CaF_{2} is ideal for any demanding applications where its high damage threshold, low fluorescence, and high homogeneity are beneficial. It is popular in excimer laser applications and frequently used in spectroscopy and cooled thermal imaging.
Click on the images below or open the table to the right to see Thorlabs’ complete selection of optics made from CaF_{2}.
F2 Specifications 
Index of Refraction^{a} 

Refractive Index at dLine (587.6 nm)^{a} 
1.620 
Sellmeier Equation^{a} 

Abbe Number (V_{d}) 
36.37 
Attenuation Coefficient 

Transmission Range 
385 nm  2 µm 
Fresnel Reflectance and Transmittance (Calculated) 

Density 
3.6 g/cm^{3} 
Knoop Hardness (100 g Load) 
420 kg/mm^{2} 
Young's Modulus 
57 GPa 
Shear Modulus (calculated value) 
23.4 GPa 
Bulk Modulus (calculated value) 
33.9 GPa 
Poisson's Ratio 
0.22 
Coefficient of Thermal Expansion 
8.2 x 10^{6} /°C 
Heat Capacity 
0.557 J/(g*K) 
Softening Point 
580°C 
Change in Index of Refraction with Temperature 
2.7 x 10^{6} /°C 
F2 is a flint glass that offers excellent performance in the visible and NIR spectral ranges. It is is characterized by a high refractive index and low Abbe number, making it excellent for use as an equilateral dispersive prism. Compared to NSF11, it offers superior chemical resistance and slightly higher transmission. F2 has a transmission range from 385 nm to 2 µm and a refractive index of 1.620 at 587.6 nm.
Click on the images below or open the table to the right to see Thorlabs’ complete selection of optics made from F2.
Germanium Specifications 
Index of Refraction^{a} 

Index of Refraction at CO_{2} Line (10.6 µm)^{a} 
4.004 
Sellmeier Equation^{a} 

Abbe Number (V_{d}) 
Not Defined 
Transmission Range 
2.0  16 µm 
Fresnel Reflectance and Transmittance (Calculated) 

Density 
5.33 g/cm^{3} 
Knoop Hardness 
780 kg/mm^{2} 
Young's Modulus 
102.7 GPa 
Shear Modulus 
67.04 GPa 
Bulk Modulus 
77.2 GPa 
Poisson's Ratio 
0.278 
Coefficient of Thermal Expansion 
6.1 x 10^{6} /°C 
Heat Capacity 
0.310 J/(g*K) 
Melting Point 
936 °C 
Change in Index of Refraction with Temperature (@ 10.6 μm) 
277 x 10^{6} /°C 
Due to its broad transmission range (2.0  16 µm) and opacity in the visible portion of the spectrum, Germanium (Ge) is well suited for IR laser applications. This makes it an ideal choice for biomedical and military imaging applications. In addition, Ge is inert to air, water, alkalis, and acids (except nitric acid). Germanium's transmission properties are highly temperature sensitive; in fact, the absorption becomes so large that germanium is nearly opaque at 100 °C and completely nontransmissive at 200 °C. Ge has an index of refraction of 4.004 at 10.6 µm.
When handling optics, one should always wear gloves. This is especially true when working with germanium, as dust from the material is hazardous. For your safety, please follow all proper precautions, including wearing gloves when handling this material and thoroughly washing your hands afterward. Click here to download a pdf of the MSDS for germanium.
Click on the images below or open the table to the right to see Thorlabs’ complete selection of optics made from germanium.
Magnesium Fluoride Specifications 
Index of Refraction_{}^{a} 

Index of Refraction at dLine (587.6 nm)^{a} 
n_{e }= 1.378 n_{o} = 1.390 
Sellmeier Equation, Extraordinary^{a} 

Sellmeier Equation, Ordinary^{a} 

Abbe Number (V_{d}), Extraordinary 
104.86 
Abbe Number (V_{d}), Ordinary 
106.22 
Transmission Range 
200 nm  6.0 µm 
Fresnel Reflectance and Transmittance, Extraordinary (Calculated) 

Fresnel Reflectance and Transmittance, Ordinary (Calculated) 

Density 
3.177 g/cm^{3} 
Knoop Hardness 
415 kg/mm^{2} 
Young's Modulus 
138.5 GPa 
Shear Modulus 
54.66 GPa 
Bulk Modulus 
101.32 GPa 
Poisson's Ratio 
0.276 
Coefficient of Thermal Expansion 
13.70 x 10^{6} /°C (Parallel) 8.48 x 10^{6} /°C (Perpendicular) 
Heat Capacity 
1.003 J/(g*K) 
Melting Point 
1255 °C 
Change in Index of Refraction with Temperature (@ 400 nm) 
2.3 x 10^{6} /°C (Parallel) 1.7 x 10^{6} /°C (Perpendicular) 
Magnesium Fluoride (MgF_{2}) is a synthetic crystalline substrate, transparent over a wide range of wavelengths. Transmitting from 200 nm to 6.0 µm, magnesium fluoride is well suited for applications ranging from the UV to the IR. MgF_{2} is very rugged and durable, making it useful in highstress environments. It is commonly used in machine vision, microscopy, and industrial applications. Magnesium fluoride has an ordinary refractive index of 1.390 and an extraordinary refractive index of 1.378 at 587.6 nm.
Click on the images below or open the table to the right to see Thorlabs’ complete selection of optics made from MgF_{2}.
NBK7 Specifications 
Index of Refraction^{a} 

Index of Refraction at dLine (587.6 nm)^{a} 
1.517 
Sellmeier Equation^{a} 

Abbe Number (V_{d}) 
64.17 
Attenuation Coefficient 

Transmission Range 
350 nm  2.0 µm 
Fresnel Reflectance and Transmittance (Calculated) 

Density 
2.51 g/cm^{3} 
Knoop Hardness 
520 kg/mm^{2} 
Young's Modulus 
82 GPa 
Shear Modulus (Calculated Value) 
34.0 GPa 
Bulk Modulus (Calculated Value) 
46.5 GPa 
Poisson's Ratio 
0.206 
Coefficient of Thermal Expansion 
7.1 x 10^{6} /°C 
Heat Capacity 
0.858 J/(g*K) 
Softening Point 
550 °C 
Change in Index of Refraction with Temperature (+20/+40°C @ 1060 nm) 
2.4 x 10^{6} /°C 
Spherical Lenses 
PlanoConvex 
Uncoated, Unmounted 
Uncoated, Mounted 
VCoated (780, 633, 1064/532 nm) 
A Coated (350700 nm), Unmounted 
A Coated (350700 nm), Mounted 
B Coated (6501050 nm), Unmounted 
B Coated (6501050 nm), Mounted 
C Coated (10501620 nm), Unmounted 
C Coated (10501620 nm), Mounted 
BiConvex 
Uncoated 
A Coated (350700 nm) 
B Coated (6501050 nm) 
C Coated (10501620 nm) 
PlanoConcave 
Uncoated 
A Coated (350700 nm) 
B Coated (6501050 nm) 
C Coated (10501620 nm) 
BiConcave 
Uncoated / AR Coated 
Best Form 
Uncoated 
A Coated (350700 nm) 
B Coated (6501050 nm) 
C Coated (10501620 nm) 
Positive Meniscus 
Uncoated / AR Coated 
Negative Meniscus 
Uncoated / AR Coated 
Cylindrical Lenses 
PlanoConvex 
Round 
Uncoated 
A Coated (350700 nm) 
B Coated (6501050 nm) 
C Coated (10501620 nm) 
PlanoConcave 
Round 
Uncoated 
A Coated (350700 nm) 
B Coated (6501050 nm) 
C Coated (10501620 nm) 
Windows 
Flat 
Uncoated / AR Coated 
V Coated 
Wedged 
Uncoated / AR Coated 
VCoated 
Beamsplitters 
NonPolarizing Cubes 
400  700 nm, Unmounted 
700  1100 nm, Unmounted 
1100  1600 nm, Unmounted 
Mounted 
Prisms 
Retroreflectors 
Uncoated / AR Coated, Unmounted 
Uncoated / AR Coated, Mounted 
Right Angle 
Uncoated / AR Coated 
Dove 
Uncoated 
Penta 
Unmounted 
Mounted 
Roof 
Uncoated 
Wedged 
AR Coated 
Pellin Broca 
Uncoated 
Fresnel Rhomb Retarder 
Uncoated 
Polarizers 
Economy 
Unmounted 
Diffusers 
Ground Glass 
Unmounted / Mounted 
NBK7 is a RoHScompliant borosilicate crown glass. It has excellent transmission in the visible and near IR portions of the spectrum (350 nm  2.0 µm). NBK7 is probably the most common optical glass used in highquality optical components. NBK7 is a hard glass that can withstand a variety of physical and chemical stressors. It is relatively scratch and chemical resistant. It also has a low bubble and inclusion content, making it a useful glass for precision lenses. The index of refraction of NBK7 is 1.517 at 587.6 nm.
Click on the images below or open the table to the right to see Thorlabs’ complete selection of optics made from NBK7.
NSF11 Specifications 
Index of Refraction^{a} 

Index of Refraction at dLine (587.6 nm)^{a} 
1.785 
Sellmeier Equation^{a} 

Abbe Number (V_{d}) 
25.68 
Attenuation Coefficient 

Transmission Range 
420 nm  2.3 µm 
Fresnel Reflectance and Transmittance (Calculated) 

Density 
3.22 g/cm^{3} 
Knoop Hardness 
615 kg/mm^{2} 
Young's Modulus 
92 GPa 
Shear Modulus (Calculated Value) 
36.6 GPa 
Bulk Modulus (Calculated Value) 
63.1 GPa 
Poisson's Ratio 
0.257 
Coefficient of Thermal Expansion 
8.5 x 10^{6} /°C 
Heat Capacity 
0.710 J/(g*K) 
Softening Point 
592 °C 
Change in Index of Refraction with Temperature (+20/+40°C @ 1060 nm) 
0.1 x 10^{6} /°C 
NSF11 is a RoHScompliant denseflint glass that is transparent from 420 nm to 2.3 µm. This glass exhibits higher dispersion than NBK7 but many of its other properties are comparable. With a high index of refraction and a low Abbe number, NSF11 has high dispersive power and is ideal for applications in the visible range that require high dispersion. Its index of refraction is 1.785 at 587.6 nm.
Click on the images below or open the table to the right to see Thorlabs’ complete selection of optics made from NSF11.
PTFE Specifications 
Index of Refraction^{a} 
1.4 
Sellmeier Equation 
 
Abbe Number (V_{d}) 
Not Defined 
Transmission Range 
30 µm  1 mm 
Density 
2.2 g/cm^{3} 
Knoop Hardness 
 
Young's Modulus 
1.8 GPa 
Shear Modulus (calculated value) 
0.62 GPa 
Bulk Modulus (calculated value) 
7.5 GPa 
Poisson's Ratio 
0.46 
Coefficient of Thermal Expansion at 20°C 
135 x 10^{6} /°C 
Heat Capacity 
1.3 J/(g*K) 
Melting Point 
327 °C 
Change in Index of Refraction with Temperature 
 
Thorlabs provides plastic planoconvex lenses made with Polytetrafluoroethylene (Virgin White PTFE), which has a low dielectric constant of approximately 1.96 at 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 especially useful for application in the Terahertz range, which is defined as the frequency range from 300 GHz to 10 THz, or the wavelength range of 30 μm to 1 mm. 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.
Click on the image below or open the table to the right to see Thorlabs’ complete selection of optics made from PTFE.
Rutile Specifications 
Index of Refraction^{a} 

Index of Refraction at Nd:YAG (1.064 µm)^{a} 
n_{e }= 2.734 n_{o} = 2.482 
Sellmeier Equation, Extraordinary^{a} 

Sellmeier Equation, Ordinary^{a} 

Abbe Number (V_{d}), Extraordinary 
Not Defined 
Abbe Number (V_{d}), Ordinary 
Not Defined 
Transmission Range 
500 nm  4.5 µm 
Fresnel Reflectance and Transmittance, Extraordinary (Calculated) 

Fresnel Reflectance and Transmittance, Ordinary (Calculated) 

Density 
4.25 g/cm^{3} 
Knoop Hardness 
879 kg/mm^{2} 
Young's Modulus* 
 
Shear Modulus 
112.4 GPa 
Bulk Modulus 
215.5 GPa 
Poisson's Ratio 
0.28 
Coefficient of Thermal Expansion 
9.2 x 10^{6} /°C (Parallel) 7.1 x 10^{6} /°C (Perpendicular) 
Heat Capacity 
0.711 J/(g*K) 
Melting Point 
1840°C 
Change in Index of Refraction with Temperature 
0.42 x 10^{6} /°C (Parallel) 0.72 x 10^{6} /°C (Perpendicular) 
Rutile's (TiO_{2}) durability, high refractive index, and strong birefringence make it a useful substrate in the fabrication of polarizers. Our rutile polarizers offer extremely pure polarization of light with a 100,000:1 extinction ratio. They are meant for use with lasers in the 2.2 μm to 4 μm wavelength range and have an airspaced design. The transmission data above was taken through an uncoated 4 mm thick sample of zcut rutile. Rutile has an extraordinary refractive index of 2.734 and an ordinary refractive index of 2.482 at 1.064 μm.
Click on the images below or open the table to the right to see Thorlabs’ complete selection of optics made from rutile.
Sapphire Specifications 
Index of Refraction^{a} 

Index of Refraction at Nd:YAG (1.064 µm)^{a} 
n_{e} = 1.747 n_{o} = 1.754 
Sellmeier Equation, Extraordinary^{a} 

Sellmeier Equation, Ordinary^{a} 

Abbe Number (V_{d}), Extraordinary 
72.99 
Abbe Number (V_{d}), Ordinary 
72.31 
Transmission Range 
150 nm  4.5 µm 
Fresnel Reflectance and Transmittance, Extraordinary (Calculated) 

Fresnel Reflectance and Transmittance, Ordinary (Calculated) 

Density 
3.97 g/cm^{3} 
Knoop Hardness 
2000 kg/mm^{2} 
Young's Modulus 
335 GPa 
Shear Modulus 
148.1 GPa 
Bulk Modulus 
240 GPa 
Poisson's Ratio 
0.25 
Coefficient of Thermal Expansion 
5.3 x 10^{6} /°C (Parallel) 4.5 x 10^{6} /°C (Perpendicular) 
Heat Capacity 
0.335 J/(g*K) 
Softening Point 
1800 °C 
Change in Index of Refraction with Temperature (@ 0.546 μm) 
13.1 x 10^{6}/°C 
Sapphire (Al_{2}O_{3}) has exceptional surface hardness and can only be scratched by a few materials other than itself. This hardness allows it to be made into much thinner optics than other substrates. Sapphire is chemically inert and insoluble to water, common acids, and alkalis for temperatures up to 1,000 °C. Sapphire is transparent in the UV to the IR (150 nm  4.5 µm). It is commonly used in IR laser systems and has an ordinary refractive index of 1.754 and an extraordinary refractive index of 1.747 at 1.064 µm.
Click on the images below or open the table to the right to see Thorlabs’ complete selection of optics made from sapphire.
Silicon Specifications 
Index of Refraction^{a} 

Index of Refraction at 4.58 µm^{a} 
3.423 
Sellmeier Equation^{a} 

Abbe Number (V_{d}) 
Not Defined 
Transmission Range 
1.2  8.0 µm 
Fresnel Reflectance and Transmittance (Calculated) 

Density 
2.329 g/cm^{3} 
Knoop Hardness 
1100 kg/mm^{2} 
Young's Modulus 
130.91 GPa 
Shear Modulus 
79.92 GPa 
Bulk Modulus 
101.97 GPa 
Poisson's Ratio 
0.28 
Coefficient of Thermal Expansion 
4.50 x 10^{6} /°C 
Heat Capacity 
0.84 J/(g*K) 
Melting Point 
1690 °C 
Change in Index of Refraction with Temperature (@ 10.6 μm) 
160 x 10^{6} /°C 
Silicon (Si) lenses and windows are an ideal choice for applications using wavelengths in the nearIR range and parts of the midIR range. Silicon offers high thermal conductivity and low density, making it suitable for laser mirrors. However, since silicon has a strong absorption band at 9 µm, it is not suitable for use with CO_{2} laser transmission applications. Silicon optics are also particularly well suited for imaging, biomedical, and military applications. Our Quantum Cascade Lasers offer a number of output wavelengths for use with silicon optics. Silicon has a transmission range from 1.2 µm to 8.0 µm. Silicon has a refractive index of 3.423 at 4.58 µm.
Click on the images below or open the table to the right to see Thorlabs’ complete selection of optics made from silicon.
UV Fused Silica Specifications 
Index of Refraction^{a} 

Index of Refraction at dLine (587.6 nm)^{a} 
1.458 
Sellmeier Equation^{a} 

Abbe Number (V_{d}) 
67.82 
Transmission Range 
185 nm  2.1 µm 
Fresnel Reflectance and Transmittance (Calculated) 

Density 
2.203 g/cm^{3} 
Knoop Hardness 
461 kg/mm^{2} 
Young's Modulus 
73.6 GPa 
Shear Modulus (Calculated Value) 
31.4 GPa 
Bulk Modulus (Calculated Value) 
37.2 GPa 
Poisson's Ratio 
0.17 
Coefficient of Thermal Expansion 
0.55 x 10^{6} /°C 
Heat Capacity 
0.736 J/(g*K) 
Softening Point 
1585 °C 
Change in Index of Refraction with Temperature (+20/+40°C @ 1060 nm) 
11.9 x 10^{6} /°C 
UVGrade Fused Silica (UVFS) is ideal for use in applications in the UV range that go beyond the transmission of NBK7. When compared to NBK7, UV fused silica is transparent over a wider range of wavelengths (185 nm  2.1 µm) and also offers a lower index of refraction as well as better homogeneity. It is scratch resistant and has a low coefficient of thermal expansion. UV fused silica exhibits minimal fluorescence when exposed to wavelengths longer than 290 nm. Its index of refraction is 1.458 at 587.6 nm.
Click on the images below or open the table to the right to see Thorlabs’ complete selection of optics made from UVFS.
Yttrium Orthovanadate Specifications 
Index of Refraction^{a} 

Index of Refraction at Nd:YAG (1.064 µm)^{a} 
n_{o} = 1.959 n_{e }= 2.166 
Sellmeier Equation, Extraordinary^{a} 

Sellmeier Equation, Ordinary^{a} 

Abbe Number (V_{d}), Extraordinary 
18.10 
Abbe Number (V_{d}), Ordinary 
20.29 
Transmission Range 
488 nm  3.4 µm 
Fresnel Reflectance and Transmittance, Extraordinary (Calculated) 

Fresnel Reflectance and Transmittance, Ordinary (Calculated) 

Density 
4.23 g/cm^{3} 
Knoop Hardness 
480 kg/mm^{2} 
Young's Modulus 
133 GPa 
Coefficient of Thermal Expansion 
11 x 10^{6} /°C (Parallel) 4.4 x 10^{6} /°C (Perpendicular) 
Heat Capacity 
0.51 J/(g*K) 
Melting Point 
1750  1940 °C 
Change in Index of Refraction with Temperature (@ 632.8 nm) 
2.9 x 10^{6} /°C (Parallel) 8.5 x 10^{6} /°C (Perpendicular) 
Yttrium Orthovanadate (YVO_{4}) is a positive uniaxial crystal that is primarily used for polarization optics. It has a large birefringence and a wide transparency range that extends into the infrared, making it ideal for IR polarizers.
Click on the images below or open the table to the right to see Thorlabs’ complete selection of optics made from yttrium orthovanadate.
Zerodur^{®} Specifications 
Index of Refraction^{a} 

Index of Refraction at dLine 587.6 nm^{a} 
1.542 
Sellmeier Equation^{a} 

Abbe Number (V_{d}) 
56.12 
Fresnel Reflectance and Transmittance (Calculated) 

Density 
2.53 g/cm^{3} 
Knoop Hardness 
620 kg/mm^{2} 
Young's Modulus 
90.3 GPa 
Shear Modulus (Calculated Value) 
36.4 GPa 
Bulk Modulus (Calculated Value) 
57.9 GPa 
Poisson's Ratio 
0.24 
Coefficient of Thermal Expansion 
0 ± 0.100 x 10^{6} /°C 
Heat Capacity 
0.80 J/(g*K) 
Maximum Application Temperature 
600 °C 
Zerodur^{®} is a glass ceramic with an extremely low coefficient of thermal expansion (CTE). This material is produced by Schott, and is used to manufacture mirrors for demanding applications that are sensitive to thermallyinduced drift. Chemically, it is an inorganic, nonporous lithium aluminum silicon oxide glass ceramic that consists of evenly distributed nanoscale crystals in a glass phase. It displays excellent CTE homogeneity and chemical stability, and is frequently utilized in highprecision optical systems. Transmission data and specifications are not provided for Zerodur because Thorlabs only offers reflective Zerodur optics.
Click on the images below or open the table to the right to see Thorlabs’ complete selection of optics made from Zerodur.
Zinc Selenide Specifications 
Index of Refraction^{a} 

Index of Refraction at CO_{2} Line (10.6 µm)^{a} 
2.403 
Sellmeier Equation^{a} 

Abbe Number (V_{d}) 
Not Defined 
Transmission Range 
600 nm  16 µm 
Fresnel Reflectance and Transmittance (Calculated) 

Density 
5.27 g/cm^{3} 
Knoop Hardness 
112 kg/mm^{2} 
Young's Modulus 
67.2 GPa 
Shear Modulus* 
34 GPa 
Bulk Modulus 
40 GPa 
Poisson's Ratio 
0.28 
Coefficient of Thermal Expansion 
7.1 x 10^{6} /°C 
Heat Capacity 
0.399 J/(g*K) 
Melting Point 
1520 °C 
Change in Index of Refraction with Temperature (@ 10.6 μm) 
61 x 10^{6} /°C 
Due to its wide transmission band and low absorption in the red portion of the visible spectrum, Zinc Selenide (ZnSe) is commonly used in optical systems that combine CO_{2} lasers, operating at 10.6 µm, with inexpensive HeNe alignment lasers. Zinc selenide is transparent from 600 nm  16 µm and is ideal for IR applications. It is also commonly used in thermal imaging systems. ZnSe also transmits some visible light, unlike germanium and silicon, thereby allowing for visual optical alignment. However, it is quite soft and will scratch easily. ZnSe has an index of refraction of 2.403 at 10.6 µm.
When handling optics, one should always wear gloves. This is especially true when working with zinc selenide, as it is a hazardous material. For your safety, please follow all proper precautions, including wearing gloves when handling ZnSe and thoroughly washing your hands afterward. For the MSDS for ZnSe in English, click here, and for the MSDS in Japanese, click here.
Click on the images below or open the table to the right to see Thorlabs’ complete selection of optics made from ZnSe.
Thorlabs offers a wide range of achromatic lenses with wavelength options ranging from 240 nm to 12 µm. The table below lists the various substrates used in Thorlabs' achromatic lenses. Click here to view Thorlabs' full line of achromatic lenses.
Achromatic Substrate Specifications 
Substrate 
Uncoated Transmission Range 
Uncoated Transmission Graph 
Attenuation Coefficient 
Abbe Number, V_{d} 
Density (g/cm^{3}) 
Knoop Hardness (kg/mm^{2}) 
Young Modulus (GPa) 
Shear Modulus^{a} (GPa) 
Bulk Modulus^{a} (GPa) 
Poisson's Ratio 
CTE^{b} (x 10^{6} /°C) 
Specific Heat (J/(g*K)) 
T_{g}^{c} (°C) 
dn/dT^{d} (x 10^{6} /°C) 
CaF_{2} 
180 nm  8.0 µm 

 
95.31 
3.18 
158 
75.8 
33.77^{e} 
82.71^{e} 
0.26 
18.85 
0.854 
1418 
10.6 
UVFS 
185 nm  2.1 µm 

 
67.82 
2.2 
461 
73.6 
31.5 
37.2 
0.17 
0.55 
0.736 
~1200 
11.9 
NBK7 
350 nm  2 µm 


64.17 
2.51 
610 
82 
34.0 
46.5 
0.206 
7.1 
0.858 
557 
2.4 
NK5 
350 nm  2.1 µm 


59.48 
2.59 
3.03 
71 
29.0 
42.9 
0.224 
8.2 
0.783 
546 
1.4 
NKZFS5 
350 nm  2.1 µm 


39.7 
3.04 
555 
89 
35.8 
57.7 
0.243 
6.4 
0.73 
584 
4.2 
NLAK22 
350 nm  2.1 µm 


55.89 
3.77 
600 
90 
35.5 
64.1 
0.266 
6.6 
0.55 
689 
2.4 
NSK2 
350 nm  2.3 µm 


56.65 
3.55 
550 
78 
30.9 
54.9 
0.263 
6 
0.595 
659 
3.6 
NSSK2 
350 nm  2.3 µm 


53.27 
3.53 
570 
82 
32.5 
57.2 
0.261 
5.8 
0.58 
653 
4.3 
NSSK5 
350 nm  2.2 µm 


50.88 
3.71 
590 
88 
34.4 
66.1 
0.278 
6.8 
0.574 
645 
2.2 
SF2 
350 nm  2.2 µm 


33.85 
3.86 
410 
55 
22.4 
33.6 
0.227 
8.4 
0.498 
441 
2.7 
SF5 
350 nm  2.3 µm 


32.21 
4.07 
410 
56 
22.7 
35.0 
0.233 
8.2 
 
425 
3.5 
ZnS 
370 nm  13 µm 

 
19.86 
4.09 
160 
74.5 
 
 
0.28 
6.5 
0.515 
1765 
38.7 @ 3.39 µm 
FD10 (SF10) 
400 nm  2.3 µm 


28.41 
4.28 
430 
64 
26.1 
39.8 
0.232 
 
0.465 
454 
7.5 
LAFN7 
400 nm  2 µm 


34.95 
4.38 
520 
80 
31.3 
60.6 
0.28 
5.3 
 
500 
6.3 
NBAF10 
400 nm  2.1 µm 


47.11 
3.75 
620 
89 
35.0 
64.8 
0.271 
6.2 
0.56 
660 
3.8 
NBAF4 
400 nm  2.1 µm 


43.72 
2.89 
610 
85 
34.5 
52.7 
0.231 
7.2 
0.74 
580 
2.2 
NBAF52 
400 nm  2.1 µm 


46.6 
3.05 
2.42 
86 
34.8 
54.5 
0.237 
6.9 
0.68 
594 
2.3 
NBAK4 
400 nm  2.2 µm 


43.72 
2.89 
610 
85 
34.5 
52.7 
0.231 
7 
0.74 
580 
7.2 
NBALF4 
400 nm  2.3 µm 


53.87 
3.11 
540 
77 
30.9 
50.3 
0.245 
6.5 
0.69 
578 
4.2 
NF2 
400 nm  2.1 µm 


36.36 
2.65 
600 
82 
33.4 
50.2 
0.228 
7.8 
0.81 
569 
2.1 
NKZFS8 
400 nm  2.2 µm 


34.7 
3.2 
570 
103 
41.3 
68.1 
0.248 
7.8 
0.76 
509 
2.4 
NLAK10 
400 nm  2 µm 


50.62 
3.69 
780 
116 
45.1 
90.3 
0.286 
5.7 
0.64 
636 
4.2 
NSF1 
400 nm  2 µm 


29.62 
3.03 
540 
90 
36.0 
60.0 
0.25 
9.1 
0.75 
553 
0 
NSF2 
400 nm  2.3 µm 


33.82 
2.72 
539 
86 
34.9 
53.3 
0.231 
6.7 
0.69 
608 
2.6 
NSF4 
400 nm  2.1 µm 


27.38 
3.15 
520 
90 
35.8 
61.5 
0.256 
9.5 
0.76 
570 
0.7 
NSF5 
400 nm  2.2 µm 


32.25 
2.86 
620 
87 
35.2 
55.1 
0.237 
7.9 
0.77 
578 
1.8 
NSF6HT 
400 nm  2.1 µm 


25.36 
3.37 
550 
93 
36.8 
65.1 
0.262 
9 
0.69 
589 
0.8 
NSF8 
400 nm  2.1 µm 


31.31 
2.9 
600 
88 
35.3 
57.5 
0.245 
8.6 
0.77 
567 
0.9 
NSF10 
400 nm  2.3 µm 


28.53 
3.05 
540 
87 
34.7 
58.5 
0.252 
9.4 
0.74 
559 
0.5 
NSSK8 
400 nm  2.1 µm 


49.83 
3.27 
570 
84 
33.6 
56.2 
0.251 
7.2 
0.64 
616 
2.0 
SF6HT 
400 nm  2.3 µm 


25.43 
5.18 
370 
55 
22.1 
35.8 
0.244 
8.1 
0.389 
423 
6.8 
SF10 
400 nm  2.3 µm 


28.41 
4.28 
430 
64 
26.0 
39.8 
0.232 
7.5 
0.465 
454 
5.3 
NSF11 
420 nm  2.3 µm 


25.68 
3.22 
615 
92 
36.6 
63.1 
0.257 
8.5 
0.71 
592 
0.1 
NSF56 
450 nm  2.2 µm 



26.1 
3.28 
560 
91 
36.3 
61.9 
0.255 
8.7 
0.7 
592 
0.3 
NSF57 
450 nm  2.1 µm 


23.78 
3.53 
520 
96 
38.1 
66.7 
0.26 
8.5 
0.66 
629 
0.5 
ZnSe 
600 nm  16 µm 

 
 
5.27 
112 
67.2 
 
40.0^{e} 
0.28 
7.1 
0.399 
1520 
61 @ 10.6 µm 
Silicon 
1.2 µm  8.0 µm 

 
 
2.33 
1150 
131 
79.9^{e} 
102.0^{e} 
0.266 
4.5 
0.703 
1417 
160 @ 10.6 µm 
Germanium 
2.0  16 µm 

 
 
5.33 
780 
102.7 
67^{e} 
77.2^{e} 
0.28 
6.1 
0.31 
936 
277 @ 10.6 µm 
EBAF11 
 
 

48.31 
 
560 
92.9 
36.5 
68.5 
0.274 
69 
 
 
3.9 @ 6.43 nm 
Thorlabs offers molded plastic, molded glass, and precisionpolished aspherical lenses. Listed below are the various substrates used in Thorlabs' aspheric lenses. Click here to view Thorlabs' full line of aspheric lenses.
Aspheric Substrate Specifications 
Substrate 
Uncoated Transmission Range 
Uncoated Transmission Graph 
Attenuation Coefficient 
Abbe Number, V_{d} 
Density (g/cm^{3}) 
Knoop Hardness (kg/mm^{2}) 
Young Modulus (GPa) 
Shear Modulus^{a} (GPa) 
Bulk Modulus^{a} (GPa) 
Poisson's Ratio 
CTE^{b} (x 10^{6} /°C) 
Specific Heat (J/(g*K)) 
T_{g}^{c } (°C) 
dn/dT^{d} (x 10^{6} /°C) 
Acrylic 
380 nm  1.6 µm 

 
52.6 
1.18 
 
3.2 
1.2 
3.6 
0.35 
70 
1.465 
100 
85 
DK59 
380 nm  2 µm 

 
63.1 
 
 
 
 
 
 
6.5 
 
 
4.3 
HLAK54 
380 nm  2.05 µm 

 
51.05 
4.01 
770 
113.87 
44.0 
92.1 
0.294 
5.2 
0.528 
639 
5.7 @ 1014 nm 
Polycarbonate 
380 nm  1.6 µm 

 
27.56 
1.21 
 
2.24 
0.82 
2.9 
0.37 
70.2 
1.3 
130 
107 
B270 
380 nm  2.1 µm 

 
58.64 
2.54 
5.37 
74 
30.3 
44.5 
0.223 
 
 
 
 
Cyclic Olefin Copolymer 
400 nm  1.50 µm 

 
56 
1.02 
 
3.1 
1.1 
4.0 
0.37 
60 
 
140 
101 
HZLAF52 
400 nm  2 µm 

 
40.95 
4.45 
650 
111.46 
42.6 
96.3 
0.307 
6.2 
0.507 
599 
6.4 @ 1014 nm 
SLAH64 
400 nm  1.9 µm 

 
47.3 
4.3 
750 
122.4 
47.3 
99.0 
0.294 
6.1 
0.491 
685 
3.7 @ 1014 nm 
SLAL13 
400 nm  2 µm 

 
53.34 
3.6 
650 
107.3 
41.6 
85.2 
0.29 
5.3 
0.574 
641 
4.9 @ 1014 nm 
TAC4 
400 nm  1.9 µm 

 
51.05 
406 
765 
112.5 
43.3 
93.8 
0.3 
5.2 
0.528 
630 
 
ECO550 
400 nm  1.7 µm 

 
50.28 
3.31 
254 
55.1 
27.6 
18.4 
 
11.62 
 
371 
1.3 
NSF57 
450 nm  2 µm 


23.78 
3.53 
520 
96 
38.1 
66.7 
0.26 
8.5 
0.66 
629 
0.5 
SNPH1 
450 nm  2 µm 

 
22.76 
3.29 
460 
89.3 
35.72^{d} 
59.5^{d} 
0.25 
8.3 
 
552 
1.8 @ 1014 nm 
ZnSe 
600 nm  16 µm 

 
 
5.27 
112 
67.2 
n/a 
40^{e} 
0.28 
7.1 
0.399 
1520 
61 @ 10.6 μm 
BD2 
1.2 µm  12 µm 

 
 
4.67 
150 
22.1 
11.1 
7.4 
 
13.5 
 
278 
91 
DZLAF52LA 
 

 
40.73 
4.56 
662 
11.506 
5.8 
3.8 
 
6.9 
 
546 
6.5 
DZK3 
 

 
60.71 
2.83 
628 
97.67 
39.6 
61.2 
0.234 
7.6 
0.816 
511 
2.3 @ 1014 nm 