http://people.csail.mit.edu/jafferFreeSnell/dielectric.html
	All-Dielectric Optics
	Refractive Index Spectra. Sources nk spectral database management script All-Dielectric Optics Bandpass Filter Polarizers Anti-Reflection Coatings Dielectric Mirrors Metal Films Thick Reflective Metal Thin Metal Films Matching Measured Data Granular Metal Films IRG-II GranFilm The Colors of Silver and Gold Colors of Zinc Sulfide Optical Coherence Coherence Incoherence Gaussian Filtering Polyethylene Background Emissivity Absorption Lines Thin HDPE Films Thick HDPE Films

This validation suite is from "dielectric.scm", part of the FreeSnell package. "dielectric.log" is the text generated by running dielectric.scm:

scm -l dielectric.scm > dielectric.log

Bandpass Filter

Here is a 47-layer Wide Infrared Bandpass Filter produced by Software Spectra, Inc.'s TFCalc program, which incrementally optimized its design.

TFCalc
FreeSnell

Polarizers

In "Immersed Wide-Angle Polarizer" the blue region is the envelope of many wavelengths swept over angle of incidence.

TFCalc
FreeSnell

In "New Thin Film Polarizing Beamsplitter" looks at angles from 65 to 75 degrees while sweeping over wavelength.

TFCalc
FreeSnell

Anti-Reflection Coatings

There are two "6-layer antireflection coatings" in "Basics of Optics of Multilayer Systems" from OptiLayer Thin Film Software

OptiLayer
FreeSnell

This "8-layer antireflection coating" is from "Basics of Optics of Multilayer Systems" from OptiLayer Thin Film Software

OptiLayer
FreeSnell

"Growing an Antireflection Coating" from Software Spectra, Inc. does not exactly match; but is close.

TFCalc
FreeSnell

Dielectric Mirrors

JK Consulting
FreeSnell

"Cold Mirror" from JK Consulting is a stack:

G 1.2(.5H L .5H)5 1.0(.5H L .5H)5 0.8(.5H L .5H)5 2L

where:

• G is the glass substrate;
• L is 1/4 wavelength of SiO₂;
• H is 1/4 wavelength of TiO₂; and
• 1.0 is the nominal wavelength, 550.nm.

Although it acts as a mirror, this design is composed entirely of dielectric materials.

JK Consulting
FreeSnell

The FreeSnell stack is written:

(optical-stack (substrate 1)
               (nominal nom)
               (layer SiO2 1/2)
               (nominal (* 0.8 nom))
               (repeat 5
                       (layer TiO2 1/8)
                       (layer SiO2 1/4)
                       (layer TiO2 1/8))
               (nominal (* 1.0 nom))
               (repeat 5
                       (layer TiO2 1/8)
                       (layer SiO2 1/4)
                       (layer TiO2 1/8))
               (nominal (* 1.2 nom))
               (repeat 5
                       (layer TiO2 1/8)
                       (layer SiO2 1/4)
                       (layer TiO2 1/8))
               (substrate glass))

"Cold Mirror" from Software Spectra, Inc.'s TFCalc program.

TFCalc
FreeSnell

TFCalc
FreeSnell

"Broadband High-Reflection Coating at 50 Degrees" from Software Spectra, Inc.'s TFCalc program.

TFCalc
FreeSnell

"Dielectric Omnidirectional Reflector" from Software Spectra, Inc.'s TFCalc program treats the metal Tellurium as a dielectric with a fixed index of refraction. FreeSnell matches well midband; less so elsewhere.

TFCalc
FreeSnell

The next section tests FreeSnell's modeling of metal films.