I can plot a thin spiral using just:

$ r=\frac{\theta }{2 \pi };$

PolarPlot[theta/2 Pi,{theta,0,2 Pi}] 

but is there a way to plot a spiral that has actual area (not just a visually thicker line, but actual 2D spiral as if you took a long rectangle and curled it up, if that makes sense...)? Like these:

Essentially, I'm trying to bounce a beam of light off a lens which has this pattern machined out of it, so I need to be able to modify the thickness of the trenches to see how much light will get reflected. The beam of light is estimated as a matrix of points. So I need to have this pattern also represented as a matrix.

___________________ FOLLOWUP TO THE QUESTION : _____________________

Does anyone know how I could quantify the thickness of the spiral AND the thickness of the empty space between the arms? I know that right now it depends on the value put into the AbsoluteThickness, but I need to be able to put in a number in, say, nanometers. Does anyone have any ideas on this might be done?

______END OF FOLLLOWUP

I can plot a thin spiral using just:

$ r=\frac{\theta }{2 \pi };$

PolarPlot[theta/2 Pi,{theta,0,2 Pi}] 

but is there a way to plot a spiral that has actual area (not just a visually thicker line, but actual 2D spiral as if you took a long rectangle and curled it up, if that makes sense...)? Like these:

Essentially, I'm trying to bounce a beam of light off a lens which has this pattern machined out of it, so I need to be able to modify the thickness of the trenches to see how much light will get reflected. The beam of light is estimated as a matrix of points. So I need to have this pattern also represented as a matrix.

I can plot a thin spiral using just:

$ r=\frac{\theta }{2 \pi };$

PolarPlot[theta/2 Pi,{theta,0,2 Pi}] 

but is there a way to plot a spiral that has actual area (not just a visually thicker line, but actual 2D spiral as if you took a long rectangle and curled it up, if that makes sense...)? Like these:

Essentially, I'm trying to bounce a beam of light off a lens which has this pattern machined out of it, so I need to be able to modify the thickness of the trenches to see how much light will get reflected. The beam of light is estimated as a matrix of points. So I need to have this pattern also represented as a matrix.

also, completely unrelated ... my head just exploded XD

I can plot a thin spiral using just:

$ r=\frac{\theta }{2 \pi };$

PolarPlot[theta/2 Pi,{theta,0,2 Pi}] 

but is there a way to plot a spiral that has actual area (not just a visually thicker line, but actual 2D spiral as if you took a long rectangle and curled it up, if that makes sense...)? Like these:

Essentially, I'm trying to bounce a beam of light off a lens which has this pattern machined out of it, so I need to be able to modify the thickness of the trenches to see how much light will get reflected. The beam of light is estimated as a matrix of points. So I need to have this pattern also represented as a matrix.