Can materials act as a low pass filter for laser beams?

AI Thread Summary
Materials can block or weaken laser beams, but the discussion centers on whether a material exists that acts as a low pass filter, allowing lower intensity beams to pass while blocking higher intensity ones. Nonlinear effects, such as saturation, could theoretically contribute to this behavior, but they also risk reducing high-intensity beams to lower intensities, allowing them to pass through. The conversation raises questions about the feasibility of such materials, likening them to sci-fi shields that block lasers while remaining transparent. Ultimately, the existence of a material that selectively filters laser intensities remains uncertain. The exploration of this concept highlights the complexities of laser-material interactions.
m0022l
Messages
2
Reaction score
0
There are materials which block laser beams (or light globally) or weaken its intensity via shading i.e. a beam must have crossed a specific energy barrier in order to pass this shading where beams with less energy will fade and won't pass. The question is, is there a material or a type of shading which does the opposite? Meaning that it blocks beams with intensities higher than a specific barrier and allows those with less intensities (behaving like a low pass filter somehow), does this type of material exist?!
 
Science news on Phys.org
i.e. a beam must have crossed a specific energy barrier in order to pass this shading where beams with less energy will fade and won't pass.
Are you thinking about nonlinear effects like saturation here?

I see an obvious issue for the opposite effect: If you weaken your high-intensity beam with some nonlinear effect, it becomes a low-intensity beam after a while (as no interaction will be point-like) and could pass.
Multi-photon processes depend on the beam intensity, but a beam with a higher intensity will keep a higher intensity, even if it is weakened more than a low-intensity beam.
 
Is this a question about scifi shields? You can see though it, but it blocks laser?
 
Thread 'A quartet of epi-illumination methods'
Well, it took almost 20 years (!!!), but I finally obtained a set of epi-phase microscope objectives (Zeiss). The principles of epi-phase contrast is nearly identical to transillumination phase contrast, but the phase ring is a 1/8 wave retarder rather than a 1/4 wave retarder (because with epi-illumination, the light passes through the ring twice). This method was popular only for a very short period of time before epi-DIC (differential interference contrast) became widely available. So...
I am currently undertaking a research internship where I am modelling the heating of silicon wafers with a 515 nm femtosecond laser. In order to increase the absorption of the laser into the oxide layer on top of the wafer it was suggested we use gold nanoparticles. I was tasked with modelling the optical properties of a 5nm gold nanoparticle, in particular the absorption cross section, using COMSOL Multiphysics. My model seems to be getting correct values for the absorption coefficient and...
Back
Top