Drawing a conical mirror in pst-optexp

There is no ready-to-use component for your task, but you can quite easily define your own component.

pst-optexp offers plain, curved and path interfaces (see e.g. https://tex.stackexchange.com/a/209818/33933 for an advanced example).

Here are the main steps

1. Define a new component with newOptexpDipole{conicalmirror}. You could also use newOptxpTripole. The differences in your case would only be that you need two or three nodes for positioning.

2. Define the actual appearance of the component with defconicalmirror@comp

3. Define the optical interfaces inside conicalmirror@nodes using newOptexpComp. Here, we use a PathIfc, which takes a previously defined, arbitrary path as interface using pst-intersect.

The full drawing:

documentclass[margin=5pt]{standalone}
usepackage[dvipsnames,svgnames,pdf]{pstricks}
usepackage{auto-pst-pdf}
usepackage{pst-optexp}
SpecialCoor
makeatletter
% Define a custom dipole command
newOptexpDipole{conicalmirror}
%
% Define how the dipole component is drawn
defconicalmirror@comp{%
  pspolygon[fillstyle=solid,fillcolor=gray,linestyle=none](1,-1)(0,0)(1,1)(2,1)(2,-1)
  pspolygon[fillstyle=solid,fillcolor=green!50!black,linestyle=none]%
    (1,-1)(1.1,-0.9)(0.2,0)(1.1,0.9)(1,1)(0,0)
}
% Define the optical interfaces of the component
defconicalmirror@nodes{%
  % save the path, a triangle, which defines the optical interface
  pssavepath[linestyle=none]{oenode@Path{A}}{%
    psline(1,-1)(0,0)(1,1)}
  % define the optical interface for use to draw beams
  newOptexpComp{%
    {0 0} tx@IntersectDict /PIT@name{oenode@Path{A}} get 0 0 refl {PathIfc} 1
  }%
}%
makeatother
      
begin{document}
begin{pspicture}(10,6)
  pnode(0,1){Input}
  pnode(5,1){Mirror}
  pnode(5,4){ConicalMirror}
  pnode(2,4){End1}
  pnode(8,4){End2}
  begin{optexp}
    lens[lens=3 3 2, n=1.6, compname=Lens](Input)(Mirror)
    newpsstyle{ExtendedMirror}{fillstyle=solid, fillcolor=green!50!black}
    mirror[mirrorwidth=3, linestyle=none, mirrordepth=0.1414, mirrortype=extended, compname=Mirror](Input)(Mirror)(ConicalMirror)
    conicalmirror[position=end, compname=ConicalMirror](Mirror)(ConicalMirror)
    optplate[position=end, plateheight=3, platelinewidth=0.3, compshift=-0.5, compname=End1](ConicalMirror)(End1)
    optplate[position=end, plateheight=3, platelinewidth=0.3, compshift=0.5, compname=End2](ConicalMirror)(End2)
    %
    % First, only draw the filled beam, otherwise the fillings overlap with boundary beams
    newpsstyle{Beam}{fillstyle=solid, fillcolor=red!10, linestyle=none}
    drawwidebeam[beamdiv=20, beamangle=-10.01](Input){Lens}{Mirror}{ConicalMirror}{End1}
    drawwidebeam[beamdiv=20, beamangle=10.01](Input){Lens}{Mirror}{ConicalMirror}{End2}
    %
    % now draw the boundary beams
    newpsstyle{Beam}{linecolor=red, linewidth=0.5pslinewidth}
    drawbeam[beamangle=20](Input){Lens}{Mirror}{ConicalMirror}{End2}
    drawbeam[beamangle=0.01](Input){Lens}{Mirror}{ConicalMirror}{End2}
    drawbeam[beamangle=-0.01](Input){Lens}{Mirror}{ConicalMirror}{End1}
    drawbeam[beamangle=-20](Input){Lens}{Mirror}{ConicalMirror}{End1}
  end{optexp}
end{pspicture}
end{document}