Lenses

Spherical lenses are transparent optical components consisting of one or more pieces of optical glass with surfaces curved to converge or diverge the transmitted rays from an object, thus forming a real or virtual image of that object. Lenses are classified as single lenses, cylindrical lenses and achromatic lenses according to the different applications. Dream Lasers provides these lenses with the material of BK7, fused silica, sapphire and CaF2. Special focusing systems are able to be designed by Dream Lasers' engineers upon requirement.

Lenses

Materials

Illustration

Property and Application

Plano-Convex

BK7

Fused Silica

Sapphire

CaF2

slens01.JPG (5617 bytes)

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. Also where both conjugates are on the same side of the lens, e.g. as an add-on lens to increase the numerical aperture.

Double-Convex

BK7

Fused Silica

slens02.JPG (5727 bytes)

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

BK7

Fused Silica

Sapphire

CaF2

slens03.JPG (5070 bytes)

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

slens04.JPG (5477 bytes)
Negative lens with the form most suited to producing diverging light or a virtual image, where the input light is converging.

Meniscus

BK7 Positive

slens05.GIF (3166 bytes)

These lenses may be used to increase the numerical aperture of a positive lens assembly, without an undue increase in the aberrations.

BK7 Negative

slens06.JPG (5117 bytes)

The best lens form where one conjugates is relatively far from the lens or where both conjugates are the same size of the lens.

Cylindrical

BK7

Fused Silica

slens07.JPG (7514 bytes)

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.

Achromatic

Combinations of Two Optical Grade Glasses

slens08.JPG (6077 bytes)

These lenses have considerably reduced values of spherical aberration. Coma and chromatic aberration. Best used to replace single components where performance must be improved.

Ring Mount for Lenses

Black Anodized Aluminum

slens09.JPG (8360 bytes)

Used to fix position of lenses.

Please refer to the Material Chapter for more information about BK7 glass, UV grade fused silica, Sapphire and CaF2.
Please refer to the Glossary and Technology for more information about lenses.
Please refer to Coating Chapter for more infomation of coating.
Other Material: Ge, Si, ZnSe, ZnS, MgF2, GaAs are available upon request.