Lenses |
Materials |
Illustration |
Property and Application |
Plano-convex |
Sapphire
BK7
Fused Silica
CaF2 |
|
Positive focus length. Most
suitable where one conjugate is more than five
times the other, e.g. in sensor application or
for use with near collimated light. |
Double-convex |
Sapphire
BK7
Fused Silica
CaF2 |
|
Most suitable where the conjugates
are on opposite sides of the lenses and the ratio
of the distances is less than 5:1, e.g. as simple
image relay components. |
Plano-concave |
Sapphire
Fused Silica |
|
Negative lens with the form
most suitable where one conjugates is more than
five times the other, e.g. producing divergent
light from a collimated input beam. |
Double-concave |
BK7
Fused Silica
CaF |
|
Negative lens with the form
most suited to producing diverging light or a
virtual image, where the input light is converging. |
Meniscus |
Positive |
BK7 |
|
These lenses may be used to
increase the numerical aperture of a positive
lens assembly, without an undue increase in the
aberrations. |
Negative |
BK7 |
|
The best lens form where one
conjugates is relatively far from the lens or
where both conjugates are the same size of the
lens. |
Cylindical |
BK7 Fused Silica |
|
Used to provide focusing power
in one section only. For illumination or detection
of light from line sources. Also used to anamorphic
compression of beams and images. |