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TECHSPEC^® components are designed, specified, or manufactured by Edmund Optics. Learn More

20mm Dia., 3mm Thick, VIS-NIR Coated λ/4 N-BK7 Window

Stock #45-660

$69.50

Qty 1-5
$69.50

Qty 6
$55.60

Volume Pricing
Request a Quote

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Abbe Number (v_d):

64.17

Clear Aperture (%):

Diameter (mm):

20.00 +0.0/-0.25

Thickness (mm):

3.00

Coating:

VIS-NIR (400-1000nm)

Coating Specification:

R_abs ≤0.25% @ 880nm
R_avg ≤1.25% @ 400 - 870 nm
R_avg ≤1.25% @ 890 - 1000nm

Coefficient of Thermal Expansion CTE (10^-6/°C):

7.1

Knoop Hardness (GPa):

610

Young's Modulus (GPa):

Density (g/cm³):

2.51

Index of Refraction n_d:

1.516

Parallelism (arcmin):

1.00

Poisson's Ratio:

0.206

Substrate:

N-BK7

Surface Flatness:

λ/4

Surface Quality:

60-40

Thickness Tolerance (mm):

±0.20

Type:

Protective Window

Typical Energy Density Limit:

5 J/cm² @ 532nm, 10ns

Wavelength Range (nm):

400 - 1000

Regulatory Compliance

RoHS 2015:

Compliant

Reach 209:

Compliant

Product Family Description

λ/4 Surface Flatness
Broadband Anti-Reflection Coating Options Available
Custom Coatings and Sizes Available for Volume OEM Quantities
Also Available with Laser Line V-Coats

TECHSPEC® λ/4 N-BK7 Precision Windows are ideally suited for industrial and low power laser applications. The high tolerance design yields minimal beam distortion and scatter. Broadband coating options extend the range of these precision windows through the visible and near-infrared spectra.