What does the message: 'total reflection at glass/medium interface (...)' mean?
I have an old Huygens version which shows this message when I try to generate a theoretical PSF from a data set recorded with voxel size 50x50x170 nm and the following objective features N.A. 1.2, Refract. Index 1.14.
The message means that a refractive index of 1.14 can't be combined with an NA of 1.2 because according to Snell's law NA = r.i. x sin(alpha) and sin(alpha) <= 1 so NA < 1.14 when r.i. = 1.14 for any lens.
If you specify an NA which is higher than the r.i. of the medium, then this implies total internal reflection at the glass/medium interface, causing the oblique angles of the excitation light to be reflected back into the microscope, thereby reducing the effective NA.
See also TotalInternalReflection
Huygens versions newer than 2.62 do generate a PSF even with these conditions.
Keywords: refractive index total reflection
Categories: Faq Deconvolution, Faq Microscopy, Huygens Faq, Imported Faqs
Platforms: Irix Linux Windows Mac AIX
Related products: Hu Ess Hu Pro
