1 / 19

Defining and Evaluating Multilayer Coatings in FRED

Defining and Evaluating Multilayer Coatings in FRED. Marko Swoboda. What are Multilayer Coatings?. Anti-Reflection Coatings consist of one or more layers Dielectric Mirrors use constructive/destructive interference interferometric filters select narrow lines by clever layer sequence

azriel
Download Presentation

Defining and Evaluating Multilayer Coatings in FRED

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Defining and Evaluating Multilayer Coatings in FRED Marko Swoboda

  2. What are Multilayer Coatings? • Anti-Reflection Coatings consist of one or more layers • Dielectric Mirrors use constructive/destructive interference • interferometric filters select narrow lines by clever layer sequence • required: • precise control of optical layer thickness • homogeneous deposition of dielectric/optical media

  3. Examples of Coatings • Narrow-band Interferometric Filter: • Distributed Bragg-Reflector: 8(l/4) l/2 4(l/4) 4(l/4)

  4. What is their role in FRED? • most raytraced objects act by their refractive indices, a coating is only a few micron thick  still major influence • multilayer coatings act on the phase of the light, in reflection and transmission and achieve the highest possible reflectivities for single wavelengths • all that makes it important to include such coatings in exact simulations of any system

  5. How to make a coating? simple as that: two ways: -by clicking and typing -by script and data (also typing)

  6. Coatings by Clicking • tons of options:  focus on the most general: Thin Film Layered Coatings

  7. Coatings by Clicking • layers can be repeated in groups (e.g. lambda/4 stacks)

  8. Coatings by Clicking • 3-pair DBR • don’t forget to include the materials into your database from the standard or self-defined materials!  later

  9. Plotting Coating Properties • once defined, coatings can be added to any surface in FRED • their properties are evaluated with the plot function

  10. Plot Function Options • great number of settings • wavelength region always the maximum of present rays • polarization sensitive • amplitude AND phase of reflected light

  11. Plot Function Results: 3-pair DBR • plot function results @ 0 degree incidence • saveable as text file

  12. Other Option for Coating Definition • write a script, defining the properties:

  13. Evaluation still has to be done by hand... • click on plot coating  the filter just defined narrowband transmission peak!

  14. One more example: • DBR with high-index layer on top: reflectance

  15. One more example: • DBR with high-index layer on top: phase phase jump at design wavelength!

  16. One more example: • solution: low-index-layer on top: • phase-jump only in transmitted light!

  17. Finally: New Materials • Thin-Film layers so far are only limited by the availability of materials in the FRED-database • defining a new material from external parameters helps:

  18. Best way: Scripts generated by Matlab • get lambda, n , k values from CXRO or your favourite website

  19. Conclusion • Coatings can greatly alter the behaviour of any surface in FRED • they are defined a bit on the side, and can be evaluated independently from rays (mostly) • they are defined from either standard materials in the optical region • or from imported data (preferably with matlab) for any other wavelength region

More Related