Understand Cylindrical Lens Imaging & Refs

[0207]

can anyone help me in understanding the concept of a cylindrical lens ?
how is the imaging by a cylindrical lens different from that of a sphericaL lens?
how does one decide to use a particular lens or a system of lenses for image formation?
please suggest some good reference for this ..
thanx

 

[Dadface]

Cylindrical lenses are mainly used for demonstration/experimental purposes because they stand easily on the bench with no support and they demonstrate lens action in one plane.Apart from spectacle lenses to correct astigmatism I cannot think of any other uses for them.

 

[Andy Resnick]

Cylindrical lenses will only form an image in one axis. However, cylindrical lenses are used a lot to do things like correct astigmatism, circularize diode laser beams, and image spectrographic entrance slits. I think they are also used in anamorphic lens setups as well. More exotically, two crossed cylindrical lenses can be used to give independent magnifications in orthogonal directions.

 

[0207]

Thanks for the replies.
I am interested in perhaps some sort of a point wise distinction between the cylindrical and spherical lens imaging. A ray diagram to discuss one point would also suffice. I am constantly surfing through the internet and the book shelves for some help of this kind but I'm not getting it anywhere.
If you could elaborate the circularization of diode laser beams using cylndrical lens , or say provide a reference for it, I would be really grateful.

keeping everything aside , how can I explain the reason of picking up a cylindrical lens in an arbitrary system in place of any other lens , to an armature in this field?

 

[Andy Resnick]

http://www.rp-photonics.com/fiber_coupled_diode_lasers.html

I don't exactly understand your last sentence- do you mean an amateur? Cylindrical lenses cannot simply replace spherical lenses, they have very specific applications.

 

[0207]

I'm sorry, I meant that only ..

thanx for the help ... I'm finding it really useful.
could you also help me resolve this- consider a situation where one converges light from a long distance using some optics and obtains a circular spot(more or less) of a certain dia, now if cylindrical lens is put in its path, what is expected to be obtained?
considering the characteristic property of a cyl lens to be focusing along one axis ,does it mean that there will be an elongated oval image of this circular spot at the focus?

 

[Andy Resnick]

If the source is at infinity, at the focal plane of the cylindrical lens there will be a line (or something that looks like a line). The cross-section of the line will approximate a slice through an Airy disc.

 

[0207]

thank you for the help.