Best Form Lenses

These singlets are produced from 2 materials, i.e. fused silica or optical glass SF L57.
he optical design of these lenses is carried out in such a way that they are so called „best form lenses" for β' = 0 (M = 0, i.e. one infinite conjugate on the side of the stronger curvature and a focus in the focal plane on the side with less curvature). Such lenses have the best (least) spherical aberration which can be achieved with a (spherical) single element lens. Additionally our lenses are designed so that this correction is preserved over some amount of finite field.

Bestformlinsen/Zeichnung(2k)

Best form lenses produced from optical glass

The optical glass SF L57 (a dense flint glass produced by Schott) is particularly interesting for the visible and the infrared. It transmits very good up to about 2.7 µm. Furthermore it is virtually free of absorption bands as caused by OH-groups. With increasing absorption the transmission extends up to above 4.7 µm.
At short wavelengths transmission is limited at about 400 nm. It is only slightly yellow so that higher optical intensities can be applied above 500 nm.
Due to the high refractive index (1.83952 at 632.8 nm) these lenses have less spherical aberration than lenses from other glasses or even fused silica. With this high refractive index best form lenses are already convex-concave meniscus shaped (positive lenses; the negative ones are concave-convex). All lenses from SF L57 are designed so that they produce their nominal focal lengths at 632.8 nm.
The lenses are bevelled slightly and are delivered as standard items without AR coatings and without holders.

Positive focal length (SF L 57)to top

The center thicknesses are to be taken as guidance values only - the thicknesses may be varied up to about 1 mm from batch to batch.

Focal Length Ø max. center Thickness Ordernumber Price 1 pc. Price 2-5 pc. Price 6-10 pc.
10 mm
15 mm
20 mm
25 mm
30 mm
50 mm
75 mm
10 mm
15 mm
20 mm
25 mm
25 mm
25 mm
25 mm
4 mm
4 mm
7 mm
7 mm
6 mm
5 mm
5 mm
OBF 010
OBF 015
OBF 020
OBF 025
OBF 030
OBF 050
OBF 075
€ 80
€ 80
€ 80
€ 80
€ 87
€ 87
€ 87
€ 65
€ 65
€ 65
€ 65
€ 71
€ 71
€ 71
€ 59
€ 59
€ 59
€ 59
€ 65
€ 65
€ 65
  100 mm
  150 mm
  200 mm
  250 mm
  300 mm
  500 mm
  750 mm
1000 mm
2000 mm
25 mm
25 mm
25 mm
25 mm
25 mm
25 mm
25 mm
25 mm
25 mm
5 mm
5 mm
4 mm
4 mm
4 mm
4 mm
4 mm
4 mm
4 mm
OBF 100
OBF 150
OBF 200
OBF 250
OBF 300
OBF 500
OBF 750
OBF 999
OBF 998
€ 87
€ 87
€ 87
€ 87
€ 87
€ 87
€ 87
€ 87
€ 87
€ 71
€ 71
€ 71
€ 71
€ 71
€ 71
€ 71
€ 71
€ 71
€ 65
€ 65
€ 65
€ 65
€ 65
€ 65
€ 65
€ 65
€ 65
  100 mm
  150 mm
  200 mm
  250 mm
  300 mm
  500 mm
  750 mm
1000 mm
2000 mm
40 mm
40 mm
40 mm
40 mm
40 mm
40 mm
40 mm
40 mm
40 mm
6 mm
6 mm
6 mm
6 mm
6 mm
5 mm
5 mm
5 mm
5 mm
OBF 4.100
OBF 4.150
OBF 4.200
OBF 4.250
OBF 4.300
OBF 4.500
OBF 4.750
OBF 4.999
OBF 4.998
€ 147
€ 147
€ 147
€ 147
€ 147
€ 147
€ 147
€ 147
€ 147
€ 123
€ 123
€ 123
€ 123
€ 123
€ 123
€ 123
€ 123
€ 123
€ 115
€ 115
€ 115
€ 115
€ 115
€ 115
€ 115
€ 115
€ 115

Negative focal length (SF L 57)to top

Focal Length Ø Thickness Ordernumber Price 1 pc. Price 2-5 pc. Price 6-10 pc.
  -10 mm
  -30 mm
-100 mm
-300 mm
 10 mm
25 mm
25 mm
25 mm
3 mm
6 mm
4 mm
4 mm
OBF 0.010
OBF 0.030
OBF 0.100
OBF 0.300
€ 87
€ 87
€ 87
€ 87
€ 71
€ 71
€ 71
€ 71
€ 65
€ 65
€ 65
€ 65

Antireflection coatingsto top

  • The lenses can be AR coated for subranges of their transmission range or for single wavelengths. → on request
  • A MgF2 single layer on these lenses makes a good and comparatively broad banded AR coating: Rmin < 0.1% per surface at 633 nm and R < 1% between 550 nm and 800 nm. → on request

Available on special orderto top

  • Larger quantities → on request
  • Other focal lengths → on request
  • Other Diameters → on request
  • Individual optical correction → on request
  • Lenses made from other glasses or crystals → on request
  • Have a look at our Holders for best form lenses

Best form lenses produced from fused silicia

The fused silica lenses are made from first grade synthetic fused silica to work in a wavelength range from about 180 nm to above 3.5 µm, however with OH-absorptions at about 1.4 (T=87%), 2.3 (T=76%), 2.8 (T=0%) und 3.8 µm (T=50%). The positive focal length lenses are asymmetric biconvex lenses (negative focal length lenses are asymmetric biconcave). The lenses from fused silica are designed to have their nominal focal lengths at 308 nm.
The lenses are bevelled slightly and are delivered as standard items without AR coatings and without holders.

Positive focal length (fused silicia)to top

The center thicknesses are to be taken as guidance values only - the thicknesses may be varied up to about 1 mm from batch to batch.

Focal Length Ø Center Thickness Ordernumber Price 1 pc. Price 2-5 pc. Price 6-10 pc.
10 mm
15 mm
20 mm
25 mm
30 mm
50 mm
75 mm
8 mm
10 mm
15 mm
20 mm
20 mm
25 mm
25 mm
5 mm
4 mm
6 mm
6 mm
7 mm
6 mm
6 mm
OBS  010
OBS  015
OBS  020
OBS  025
OBS  030
OBS  050
OBS  075
€ 80
€ 80
€ 80
€ 80
€ 87
€ 87
€ 87
€ 65
€ 65
€ 65
€ 65
€ 71
€ 71
€ 71
€ 59
€ 59
€ 59
€ 59
€ 65
€ 65
€ 65
  100 mm
  150 mm
  200 mm
  250 mm
  300 mm
  500 mm
  750 mm
1000 mm
2000 mm
25 mm
25 mm
25 mm
25 mm
25 mm
25 mm
25 mm
25 mm
25 mm
4 mm
4 mm
4 mm
4 mm
4 mm
4 mm
4 mm
4 mm
4 mm
OBS  100
OBS  150
OBS  200
OBS  250
OBS  300
OBS  500
OBS  750
OBS  999
OBS  998
€ 87
€ 87
€ 87
€ 87
€ 87
€ 87
€ 87
€ 87
€ 87
€ 71
€ 71
€ 71
€ 71
€ 71
€ 71
€ 71
€ 71
€ 71
€ 65
€ 65
€ 65
€ 65
€ 65
€ 65
€ 65
€ 65
€ 65
 100 mm
  150 mm
  200 mm
  250 mm
  300 mm
  500 mm
  750 mm
1000 mm
2000 mm
40 mm
40 mm
40 mm
40 mm
40 mm
40 mm
40 mm
40 mm
40 mm
7 mm
6 mm
5 mm
5 mm
5 mm
5 mm
5 mm
5 mm
5 mm
OBS  4.100
OBS  4.150
OBS  4.200
OBS  4.250
OBS  4.300
OBS  4.500
OBS  4.750
OBS  4.999
OBS  4.998
€ 147
€ 147
€ 147
€ 147
€ 147
€ 147
€ 147
€ 147
€ 147
€ 123
€ 123
€ 123
€ 123
€ 123
€ 123
€ 123
€ 123
€ 123
€ 115
€ 115
€ 115
€ 115
€ 115
€ 115
€ 115
€ 115
€ 115

Negative Focal Length (fused silicia)to top

Focal Length Ø Edge Thickness Ordernumber Price 1 pc. Price 2-5 pc. Price 6-10 pc.
  -10 mm
  -30 mm
-100 mm
-300 mm
  8 mm
20 mm
25 mm
25 mm
3 mm
5 mm
4 mm
4 mm
OBS 0.010
OBS 0.030
OBS 0.100
OBS 0.300
€ 87
€ 87
€ 87
€ 87
€ 71
€ 71
€ 71
€ 71
€ 65
€ 65
€ 65
€ 65

Antireflection coatingsto top

  • The lenses can be AR coated for subranges of their transmission range or for single wavelengths. → on request
  • Please note that on fused silica MgF2 single layers produce only a small AR effect due to the very low and similar refractive indices of fused silica and MgF2: Rmin = 1,8% at 308 nm, per  surface.

Available on special orderto top

  • Larger quantities → on request
  • Other focal lengths → on request
  • Other Diameters → on request
  • Individual optical corrections → on request
  • Lenses made from other glasses or crystals → on request
  • Have a look at our Holders for best form lenses
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