Re: Zemax/Oslo optical index with temperature

"S Victori" <ordure_demaboitemail@xxxxxxxxxx> wrote:

Hi,

I'm working on a very simple optical design containing one lens (1 glass
(such as N-BK10 for exemple)) at different temperatures.
I'm just trying to calculate the optical index values of the glass using
Sellmeier equation and its derivative according to the temperature.
Using Zemax or Oslo at 532nm and asking for the index values for
T = -10, 0, 10, 20, 30, 40°C leads to approximatly the same results :
n(@532) = 1.500188, 1.500221; 1.500254, 1.500322; 1.500357.

When I try to do it using their formula it does not fit at all even if I
know that Zemax and Oslo always scale the index so that the air index is 1.

Does anybody has solved the simple question ?

Best regards,

SV

If under support, ask the guys at Zemax or Lambda Research

If not, I'd stick with the values from the glass catalogs.

Make sure everyone is using the same temperature scale (UNITS) C, F,
or K in the equations. I've seen a lot of mixed units in the optical
field in 30 years. Also, run a quick calculation with your calculator.
The chances the programs have errors in this area is really small as
it is a feature which has been used a lot by everyone either running a
thermal analysis or designing an athermal system.

You can also check the calculation by grabbing the free version of
KDP-2 from my web site. The thermal calculations have been in KDP-2
for over 15 years and they should be correct. KDP-2 uses the thermal
coeffecient of index change and not the sellmeier method.

Jim Klein




James E. Klein
Engineering Calculations
KDP2 Optical Design Program and Design Work
www.ecalculations.com
1-818-823-4121
1-818-507-5706 (Fax)
1377 E. Windsor Rd., #317
Glendale, CA 91205
.