Natural Science Forum / Physics / Optics / January 2007

Searching for information about infrared eye safety, most of what I find
is about lasers.  I am looking for information about the safety of the
light itself.  Diffuse UV sources can damage the eye (i.e., snowblindness)
but is there any information on diffuse IR sources?  Like UV, IR ...

Microscope Group,
I wish to present a light microscope image (LM) of A. pellucida,
with a determination of the distance between the striae. The re-
sult is compared with those obtained on various A. pellucida

Does anyone know of a tunable/cw/high power (>100 mw)/single line
laser source at 3 um or in that region?  I know there are OPO
solutions but they are devastatingly expensive.
Thanks

Can someone please tell me what I am doing wrong.  Perhaps I am not
understanding terms.
I want to figure out the total depth of field for a camera using a
Micron MT9M131 CMOS imager given different M12 lens choices.

I am working for a optical parametric oscillators laser,now I want to
define a transmission for output mirror. How to think about this issue?
If this cavity is unstabe, and are there a difference?

We would like to design a distributed Bragg reflector with certain
properties.  Sure, there are formulas for bandwidth and central
frequency, but then there are all these side peaks and whatnot.  Is
there an inexpensive software package that will plot the transmittance

I have only just joined this group, but have noticed a significant rise
in off-topic posts that really detract from what is otherwise an
excellent place to learn and talk about optics.  While I'm sure people
who post these non-optic, non-scientific posts feel that they are

I need to buy a low power (under 100 mW) laser diode with nominal
wavelenght from 880 nm to 890 nm.
I'll be gratefull if someone give me producers or seller.
Thnx in advance, Andrew :)

I'm a bit confused after reading the FAQ on CO2 laser optics -- In one
place, I read that you want the HR ROC 1-2x the length of the tube, and in
another place, you want the HR barely curved at all (10m ROC or longer). I'm
looking at doing a tube 500-1000mm long, with 3/4" or 1" ...

OK, so now some reputable companies are selling green pointers of 50 mW or
more.  Edmunds Scientifics is one:
http://scientificsonline.com/product.asp?pn=3027613&cmss=3027613
Here is the reply from their customer support:

I am working with a research group In Israel to develop a consumer
medical device for the scalp using far ir. We need to cover the head
and get a radiant flux density of around 1kW/m2 or more. We're only
able to get about half that so far. We're trying to think of new

Ok, please dont everyone get mad at me, but I just started puting this
together and I really would like to promote my new holography kit and I
think it may be something of interest to you all. I put together a web
sight, and I would also like feed back on the sight.

I am wanting to sell a laser on Ebay and obviusly don't want it to go
un-noticed.
I find that doing a search for "laser" in Ebay returns a lot of
undesireable results.

Being a former engineer, I have a rudimentary understanding of optics.
Currently, I am creating a very output bicycle light using LEDs.   I am
wondering if there are any general principals that distinguish a light's
direct output in lumens as perceived by the human eye versus its ...

One way to concentrate light on a device without lenses (or the need to
aim precisely) is to build a narrow cone (frustrum, actually) with a
reflective interior surface.  If the cone is made of solid glass and
silvered on the conical surface, then Snell's law works in your favor--