Natural Science Forum / Physics / Optics / September 2004

I have a question related to Koehler illumination:
As far as I understood, Koehler illumination means imaging the light
source to the back focal plane of the microscope's objective. In case
of a point-like light source, this would that the illuminating light

So...after many tryung to make a dc power supply for my green pointer, i
did't do anything...
I've found many schematics on Sam's laser page but...don't know english so
good ...so...

Need optical quality filters like the discontinued Kodak (Wratten)
18a in size 2" and/or interferece filters for 253 and 365nm (Hg Lines)
Any ideas welcome!
K Schmitt

Once more someone has stolen my pictures. I know they are quite pretty, but
why in the world cannot people just ask for permission? (anyway I will not
give a premission *g*). It is so easy to make nice photos......
My site:

I got a sample of a <5mW yellow laser pointer this morning.
I'm not going to go into detail about it now, but I've put up some
initial pics showing its beam with the beam from a 5mW nominal
pointer.

Hi Dean,
Either your PC has a virus or someone has spoofed your address and is
sending out an email with attached ZIP file infected with a cocktail
of viruses.

Fiber to the desktop - will it happen in enterprises?
Perhaps, but what are the killer apps out there?  Also, the 10-Gigabit
copper std. might tilt the balance towards copper...
Check out this post:

Is there someone with experiences regarding to the Lambdapro 300 / 400 /
500+ mW DPSS Laser ?
I was happy with the Lambdapro 100mW DPSS.
More power - same quality ?

Wiki as A Time Saver for Researchers
Dear All,
The intention of this message is to draw researchers attention to Wiki
as a potentially efficient new means for scientific/technical

Can someone help with my few questions. Thanks.
What properties of light are currently being used in signalling?
(first, with readily available electronic components in mind.)
Polarity, wavelength, or pusles?

We have bought APDs from OKI (model: OF3600B-C2-SFFC) and try to
biasing it from a bench-top power supply at ~40-50V.
We adjust slowly the VAPD from 0V - 40V. The APD works well. Then we
turned off the power supply (VAPD). After a few minutes, we turn it on

Hello Group - so this is where you all hang then out eh?,
Newbie here who's building a MONSTER DPSS MEAN GREEN KILLER!!" - all
together now.. ready.."YAWN! Another expensive pile of half completed
garbage coming up" you say in unison (or would that be coherence?).

How can I get it from specification from mannual ?
Thanks
HH

Can anybdy tell me how I can stop laser beams from hitting me, a cheap and
efficient way without too much technics  Thanks
  Mike

I use zmax to simulate the change of spot size through the focus. If
diffraction limited size is bigger than RMS spot size, which one I
should take?
I confused why they give these two and which is real size when I