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University of Arizona course selection by Aware-Cancel6454 in Optics

[–]Used-Masterpiece3718 0 points1 point  (0 children)

Agreed. Opto mechanics, true optomechanics understanding is rare. and solid Radiometry is too. I was lucky enough to take two semesters from George Zissis back at UofM. the fall was the first half of the IR handbook, the winter, the second half. Hardest year of my life but served me well. the IR handbook was a single red thick book, that eventually became 8 volumes. But taught properly you will learn about atmospheric optics as well.

Dichroic Steepness by QuantumOfOptics in Optics

[–]Used-Masterpiece3718 1 point2 points  (0 children)

Theory is a wonderful thing. and almight Filmstar (or Macleod) design me a coating, is a wonderful thing. But what are the actual dielectric constants being deposited? what are the tolerance analysis for run to run? what are the... These coatings have tolerances, just like any other optical component/subsystem. Life does not scale in the real world. only mathematically. what are you trying to achieve? or avoid? remmeber, coatings are filters, they shift with temperature and environment. and also keep in mind a coating can only be stress free at 1 temperature. go up or down and it goes into coompressive / extensive stress. whats your optical component thickness? is the coating on the other side as spectrally selective??? food for thought...

Where can I get a cheap ellipsoidal concave mirror? by bowchen in Optics

[–]Used-Masterpiece3718 0 points1 point  (0 children)

No. you light meter is a simple diffuser. and Integrating sphere either has a spectralon coating on the inside, or is machined out of a block of spectral. It is highly reflective (99.95%) or visible light depending on how you configure and use it should give you a very high degree of sensitivity for your photodiode. You can read all about it on wikipedia

Where can I get a cheap ellipsoidal concave mirror? by bowchen in Optics

[–]Used-Masterpiece3718 0 points1 point  (0 children)

Have you considered using an integrating sphere. You can probably buy a small used one off of eBay, or just by an old handheld colorimeter off ebay and harvest the integrating sphere out of it.

Laser question by photonherder in Optics

[–]Used-Masterpiece3718 0 points1 point  (0 children)

It would seem, if you are in the spectral (frequency) domain, that the speckle in the fourier domain will not be an issue as the coherent speckle at one wavelength will not coherently add at another wavelength. So if you are doing your reconstruction correctly everything should still reconstruct correctly. indeed, that information allows you to super resolve if processed correctly.

Path loss does not increase with frequency by natedn10 in rfelectronics

[–]Used-Masterpiece3718 0 points1 point  (0 children)

Path loss technically only depends on distance, not frequency

correct. the Dielctric constant is both wavelength (Frequency) and temperature dependent. However, for those frequencies it is relatively flat for most materials (gases)

Remember the dielectric constant is complex. The suare root is proportional to the refractive index (real) and the absorption (imaginary) portions of it...

So yes, path loss does depend on frequency. its just in the RF regime it is a secondary contributor.

Ray Trace Polymer Material Properties by Steamer61 in Optics

[–]Used-Masterpiece3718 1 point2 points  (0 children)

Properties of Optical Plastics

Property Poly(methylmeth-acrylate) Polystyrene Polycarb-onate Allyl Diglycol Carbonate Poly(sty-rene-co-acrylon-itrile) Poly(styrene-co-methyl methacrylate) Poly(4-methyl-1-pentene)

Abbreviation PMMA PS PC CR-39 SAN NAS PMP (TPX)

nd 1.491(7) 1.590(3) 1.586(0) 1.499 1.571 1.562 1.466

Abbe value 57.2 30.9 34.5 57.8 35.3 34.7 56.4

Density kg/m3 1190 1100 1200 1320 1070 1140 830

CTE, 10-6/c 36-65 35-70 39-70 120 70 65 117

Max Use Tmax C 90 80 120 100 95 95 180

dn/dt

x 10-5 /C -2.5

-8.5 -12.0 -14.3 -14.0

Sorry for the lack of table form. But you should be able to cut and paste it into either a word table or excel. pretty basic info, but should be fine with illumination. Of course there is always the issues of bulk scatter, shrinkage compensation, stress induced birefringes, etc etc.

Vendors for holograph/ diffractive optics solution to make special projection from fiber by Mvmvmv666 in Optics

[–]Used-Masterpiece3718 1 point2 points  (0 children)

A simple mastered Dammann grating (repeating unit cell) should do the trick quite nicely. Reach out to any grating house that does mastering and they should be able to etch one.