BK7 Plano-Concave Lenses

 

Concave lenses convert incoming parallel rays in diverging ray bundles that seem to originate from a single point in the object space – the so called imaginary focal point. Like plano-convex lenses these lenses minimize aberrations for absolute conjugate ratios more than 5 or less than 1/5. For this, plano-convex lenses should be placed with parallel beam entering the curved side of the lens. However such an orientation of a lens may be disadvantageous and even dangerous when a plano-concave lens is used to diverge a high power pulsed laser beam. A rest-reflexion from the curved surface will produce a real secondary focus that can damage optical elements preceding the concave lens or even causing a laser break-down at this point. By high power applications the concave surfaces should be oriented in such a way that a secondary focus is avoided.

 

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Material:    BK7
Focal Length:    +/- 2 %
Design Wavelength:    546,1 nm
Diameter Tolerance:    +0/- 0.2 mm
Centering:    < 5 min. of arc
Wavefront Distortion:    λ/10
Clear Aperture:    90 % of diameter
Surface Quality:    S/D 10-5
Antireflection Coating:    on request
Lens mounted in cell:    on request


Other dimensions and focal lengths on request: list of radii  

Part-No. Diameter    Focal Length  Price €
LPV0.5"B/-15 0.5" -15 mm 39 ,--
LPV0.5"B/-25 0.5" -25 mm 38 ,--
LPV0.5"B/-40 0.5" -40 mm 31 ,--
LPV0.5"B/-50 0.5" -50 mm 29 ,--
LPV0.5"B/-75 0.5" -75 mm 29 ,--
LPV0.5"B/-100 0.5" -100 mm 26 ,--
LPV0.5"B/-150 0.5" -150 mm 26 ,--
LPV0.5"B/-200 0.5" -200 mm 26 ,--
LPV0.5"B/-300 0.5" -300 mm 26 ,--
LPV1"B/-40 1" -40 mm 35 ,--
LPV1"B/-50 1" -50 mm 34 ,--
LPV1"B/-75 1" -75 mm 31 ,--
LPV1"B/-100 1" -100 mm 31 ,--
LPV1"B/-150 1" -150 mm 31 ,--
LPV1"B/-200 1" -200 mm 31 ,--
LPV1"B/-300 1" -300 mm 31 ,--
LPV1"B/-500 1" -500 mm 31 ,--
LPV1"B/-1000 1" -1000 mm 31 ,--
LPV2"B/-75 2" -75 mm 85 ,--
LPV2"B/-100 2" -100 mm 75 ,--
LPV2"B/-150 2" -150 mm 70 ,--
LPV2"B/-200 2" -200 mm 67 ,--
LPV2"B/-300 2" -300 mm 64 ,--
LPV2"B/-500 2" -500 mm 64 ,--
LPV2"B/-1000 2" -1000 mm 64 ,--
LPV2"B/-2000 2" -2000 mm 64 ,--
LPV2"B/-3000 2" -3000 mm 64 ,--