Recent content by rcc01

Apologies—I realized I moved on to a follow-up question before properly acknowledging your earlier comment. Thank you — I appreciate the reference, I'm going through that paper now. I can see the connection to silicon photonics and plasma-dispersion modulators, and that helps frame things...

I’m an electronics engineer trying to understand the physical limits of using free‑electron density to modulate the refractive index of a thin, transparent layer at visible wavelengths. My original thought involved a low‑density gas plasma, but based on recent feedback here, I now understand...

Thanks for the detailed calculation — this helps me understand the limits much more clearly. I wasn’t aware that the plasma frequency of lab‑scale plasmas is so far below visible frequencies, or that the resulting index change is that small. I appreciate you walking through the numbers. I’ll...

“I’m considering a fixed‑thickness plasma layer on the order of ~50 µm. The idea is to vary the electron density inside that layer to produce a small refractive‑index change, roughly Δn ≈ 0.005 at visible wavelengths, which would give about a π phase shift over the layer thickness. I’m still...

Thanks, this is very helpful. Treating it as a multilayer interference filter with one layer having a tunable dielectric constant is a very clear way to think about it. I’ll start by modeling the plasma as a finite‑thickness layer with a frequency‑dependent refractive index and look at how much...

Thanks, Andy — this really helps me understand how to frame the problem. By “thin,” I mean physically thin (micron‑scale or less) and also optically thin compared to visible wavelengths. The electron density is low enough that the plasma frequency stays well below optical frequencies, so the...

I’m trying to understand how to model EM wave propagation through a very thin, low‑density plasma layer (micron‑scale thickness). The plasma frequency is well below optical frequencies, so the layer remains transparent. My questions are: Can such a thin plasma sheet be treated using the...

Andy, thanks again — your explanation helped clarify the connection between plasma permittivity and wave propagation. I have a follow‑up question: If the plasma layer is extremely thin (on the order of microns or less) and the electron density is low enough that the plasma frequency remains...

Thank you, Andy — this is very helpful. Yes, the structure I’m considering involves a very thin gas layer, so I was hoping the plasma could be treated as a perturbation or boundary layer rather than requiring a full inhomogeneous Maxwell treatment. Your suggestion about ionospheric propagation...

Hello everyone, I’m exploring a conceptual question involving the optical behavior of micro‑plasmas in thin, sealed cavities. The idea is to use a very thin low‑pressure gas layer between two transparent substrates. When an electric field is applied, the gas forms a micro‑plasma confined within...

? Hello everyone,My name is Ronald Coleman, and I’m a retired engineer and inventor based in Temescal Valley, California. I spent many years working in advanced imaging and materials environments, and I’m now focused on exploring a new optical concept involving thin‑film structures and...