Lens for infra-red sensor
p...@nospam.inforamp.net
Hello,
Im looking for a lens for an infrared sensor. This lense ,must be able
to transmit that wavelength associated with 'heat'. I dont remember
the exact wavelength but perhaps around the 8 to 10 um region.
Also wondering what kind of material such lenses are made of.
Thanks,
Peter (remove nospam when responding)
Dale Trynor
I might be able to help and if you don't get any other replies I will
find my books on it . I think what you are looking for is the same stuff
used in infrared lasers . This can be germanium metal , that I still cant
believe it but I got some of this for .25 cents a gram from a gemstone
supplier , it is also used in passive night vision systems the type that
see using the natural infrared background radiation . I find it novel how
this metal is actually metallic in appearance and yet transparent to heat
radiation . I believe silicon is also transparent but , may be because of
its tarnish invisible to us as clear silicon dioxide ,may interfere ,
someone correct me if I'm wrong . Also zinc selenide but its also
transparent to visible light , and my memory may fail me but I think salt
is also transparent black body IR . their are some others but I need to
find that book , so if you still have trouble I'll take a look for it .
Also I have been known to make mistakes do do keep that in mind
Sencerly Dale Trynor
simon prince
In the 8-10 micron region you've got a range of materials to choose
from: zinc selenide, zinc sulfide, Germanium,KRS-5, NaCl, AgCl, KCl, KBr
and many more. However, some of their material properties leave a lot
to be desired eg. getting NaCl wet would be inconvenient :-)). The most
commonly used of the above are ZnSe, ZnS and germanium.
You should also be able to find some plastics that transmit. Check out
the FAQ at my website:
http://www.ndirect.co.uk/wavefront
Simon
Gary Orlove
Peter,
There are many lens materials available for IR sensors. The choice of
material is based on the application and the wavelength sensitivity of the
sensor. The wavelengths usually associated with "heat" run from about 1 痠
to 100 痠. This is of course debatable because the EM spectrum is
continuous. However, different sensors are available that will be able to
respond to selected sections of the IR band.
If your sensor responds to 8 to 10 痠 radiation, then germanium is usually
the preferred optical material. For best performance the germanium must
have antireflective coatings applied to it. The design of these coatings
is also based on the application and sensor.
Here are a few people you can contact for further assistance:
* Dr. Jonathan S. Kane *
* Director of R&D *
* Computer Optics Inc *
* 120 Derry Rd *
* Hudson, NH, 03051 *
* VOICE (603) 889-2116 *
* FAX (603) 889-2393 *
* e-mail : c...@jlc.net *
* web: www.jlc.net/~coi *
vlpro...@compuserve.com.
Vladimir Vaynerman,
V&L Products, Inc.
Warren Vidrine, Ph.D., Gen. Mgr. Vidrine Consulting
28111 Camino La Ronda, San Juan Capistrano, CA 92675
Telephone 1-(714)-489-8372, FAX 1-(714)-489-8379
http://www.vidrine.com/
Ron Lucier
Optical Hybrids, Inc.
134 Tucker Road
West Brookfield, MA. 01585
phone #508-867-6433
--
Best of Luck
Gary Orlove, P.E.
ASNT NDT Level III T/IR
The Academy of Infrared Thermography
89 N. Main St.
Andover, MA 01810
Tel 978-470-4544
Email: glo...@earthlink.net
John
In article <6epnh9$9...@news.inforamp.net>,
p...@nospam.inforamp.net wrote:
>Im looking for a lens for an infrared sensor. This lense ,must be
>able to transmit that wavelength associated with 'heat'. I dont
>remember the exact wavelength but perhaps around the 8 to 10 um
>region. Also wondering what kind of material such lenses are made of.
Carbon dioxide lasers emit at 10.6 um and lenses and other
transmitting components are made from Zinc Selenide, Germanium of even
rock salt (NaCl). To be effective, ZnSe should be antirefelction
coated.
John
Dale Trynor
Dale Trynor sorry I posted earlier and forgot to mention the obvious
, have you considered using the lens from an old motion sensor after all
they are made to be transparent to IR and have lens properties but I dont
know how good
p...@nospam.inforamp.net wrote:
> Hello,
>
> Im looking for a lens for an infrared sensor. This lense ,must be able
> to transmit that wavelength associated with 'heat'. I dont remember
> the exact wavelength but perhaps around the 8 to 10 um region.
> Also wondering what kind of material such lenses are made of.
>
Don Stauffer
Gary Orlove wrote:
>
> Peter,
>
snip
>
> If your sensor responds to 8 to 10 痠 radiation, then germanium is usually
> the preferred optical material. For best performance the germanium must
> have antireflective coatings applied to it. The design of these coatings
> is also based on the application and sensor.
>
> --
> Best of Luck
>
> Gary Orlove, P.E.
> Email: glo...@earthlink.net
I would recommend ZnSe instead of Germanium. Even when AR coated, Ge
can be somewhat absorptive if the lens is very thick. Modern CVD is
quite high transmittance, though like Ge it also has to be AR coated.
Also, while it used to be very expensive, ZnSe windows and elements are
almost mass produced, so the cost has dropped drastically (still much
more expensive than glass,however).
--
Don Stauffer in Minneapolis
home web site- http://home1.gte.net/stauffer/
home email- stau...@gte.net
work email- stau...@htc.honeywell.com
Paul Mathews
Polyethylene lenses are available, among other places, from Edmund
Scientific....
>> Im looking for a lens for an infrared sensor. This lense ,must be able
>> to transmit that wavelength associated with 'heat'. ....<snip>
Louis Boyd
p...@nospam.inforamp.net wrote:
>
> Hello,
>
> Im looking for a lens for an infrared sensor. This lense ,must be able
> the exact wavelength but perhaps around the 8 to 10 um region.
> Also wondering what kind of material such lenses are made of.
Edmund Scientific has plastic IR fresnel lenses which have about 60%
transmission in the 8-10 micron range. They offer 9 sizes/focal
lenghts. Cost under $20 each.
Phone 609-573-6250 and get their catalog.
Lou Boyd
Fairborn Observatory