In answer to the following letter by M.J. Tobin:
>
> I need to use an achromatic UV lens with a focal length of about 50mm.  I have
> tried several manufacturers/suppliers but with no luck (Oriel, Ealing, Melles
> Griot, CVI laser).  Can anyone suggest a manufacturer who may be able to supply
> such a lens?
> Thanks
> Mark Tobin
>
 
Very good, albeit not cheap, sources  for  any  kind  of  highest
quality UV optics (as well as optics for visible and IR)are
 
Bernhard Halle Nachfl. GmbH - Optische Werkstaetten
Hubertusstr. 10
D-121 63 Berlin-Steglitz
FRG
Phone:  +49 30 791 6077
Fax:    +49 30 791 8527
 
Continental Optical Corporation
15, Power Drive
Hauppauge, NY 11788
U.S.A.
Phone:  +1 516 582 3388
Fax:    +1 516 582 1054
 
I do not know whether these factories offer www-pages. The  Lycos
search  machine  did not manage to find any of them, when I tried
it just five minutes ago.
 
The catalogue of Bernhard Halle explicitely lists a whole set  of
stock  Doublets  or Triplets for use within the wavelength region
from VUV to IR. Continental Optics do, as  far  as  I  know  from
their  catalogue  (mine is some years old), not have these lenses
as a stock product but will design and/or produce them  according
to  the  customer's demands. CAUTION! Even if the Halle-catalogue
explicitely states this I should not  hesitate  to  mention  that
many  of  the lenses are made using crystalline quartz instead of
fused silica in order to get a  higher  refractive  index.  Since
crystalline  quartz is NOT isotropic their might be problems when
using polarized light (as e.g. laser light). Mr.  (Dr.?)  Manfred
Grindel  from  Continental  Optics  once told me that it would be
possible to use Halides, instead. Before purchasing a  lens,  one
should  discuss  this point with the resp. engineers at both fac-
tories.
 
I know that also Zeiss offers custom made lenses  of  nearly  any
kind.  However,  when  I  once asked them about a special UV lens
they recommended to first contact other, smaller companies, since
the  product  would be cheaper with those. If I would not succeed
getting the requested product from any other company they offered
to design and build it but the price would be very high.
 
We have used products of both companies in our lab and were quite
satisfied.  I do not  have any affiliation whatsoever with one of
them.
 
I hope this helps.
 
Best regards
 
Paul Johannes Helm
 
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All the information in this letter is given according to the best
of my knowledge.
No  guarantee  whatsoever  is  given  for the  correctness of any
information in this letter.
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Paul Johannes Helm
 
Mailadress:     Department Physics 4
                The Royal Insitute of Technology
                S-100 44 Stockholm
                Sweden
 
Visitingadress: Department Physics 4
                The Royal Institute of Technology
                Teknikringen 14/4tr.
                S-100 44 Stockholm
                Sweden
 
Voice:          +46 8 790 7219
Fax:            +46 8 205609
Telex:          11421 kth
WWW:            http://www.fysik4.kth.se/~johannes
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