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Optical Lenses > Spherical Bi Concave Lenses > POL-BK7-BCV-DAR785-0120-12
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| Name: | DIA12.0xTc4mm BK7 Bi-Concave Lens(DAR@785nm) |
| P/N: | POL-BK7-BCV-DAR785-0120-12 | | Keywords: | Dia12.0xTc4mm,BK7,EFL-12mm,Bi-Concave,AR/AR@785nm |
| Unit Price: |
S$110.00/pc
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| Available: |
In stock
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| Request: |
Add to Request List |
| Introduction: | Bi-Concave lenses have a negative focal length and are best used to diverge a converging beam. Similar to a Plano-Concave lens, a Bi-Concave lens can diverge a collimated beam to a virtual focus as used in a Galilean type beam expander.
But it is usually preferrable to choose a bi-concave lens if the absolute conjugate ratio (object distance divided by image distance) is close to 1. When the desired absolute magnification is either less than 0.2 or greater than 5, the tendency is to choose a plano-concave lens instead. |
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| Material: |
BK7 optical glass |
| Wavelength Range: |
350nm-2.0um |
| Design Wavelength: |
633nm (n=1.515082), Bi-concave |
| Outer Diameter: |
12.0mm (+0.0/-0.1mm) |
| Edge Thickness(Te): |
Te = 7.0, +/-0.1mm |
| Center Thickness(Tc): |
Tc = 4.0,+/-0.1mm |
| Radious of Curvature(ROC): |
Side 1: R1= -12mm(+/-1%)
Side 2: R2= -12mm (+/-1%) |
| Effective Focal Length(EFL): |
-12mm |
| Surface Quality: |
40/20 scratch and dig |
| Centration: |
<3 arc minutes |
| Clear Aperture: |
>90% |
| Coating: |
Double-side AR coated @ 785 +/-10nm, R<0.2%,0-deg AOI designed |  |
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Optical Lenses
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