\documentclass{ppex}
\nonstopmode
\usepackage [basic,optics]{circ}
\pagestyle{empty}

\begin{document}
\ResetPreambleCommands
\ReadyForTheFray
\usepackage [basic,optics]{circ}
\begin{circuit}{0}
   \nl\Laser1 {} h                    % laser
   \oa 2 r                            % optical axis
   \Polar1 {} h                       % polarizer
   \oa 2 r
   \nl\OM1 P1 {} {} {} {} h           % optical modulator
   \atpin OM1P3
   \oa 4 r
   \cc\BLens1 {} h                    % 1. lens
   \oa 2 r
   \nl\Pinhole1 {} h                  % pinhole
   \oa 7 r
   \cc\SLens2 {} h                    % 2. lens
   \oa 1 r
   \Polar2 {} h                       % analyzer
   \oa 3 r
   \oa 3 r
   \nl\BSplit1 {} + d                 % beam splitter
   \atpin BSplit1+                    % continue drawing right
   \oa 2 r
   \nl\Cam1 {camera} l                % camera
   \atpin BLens1: \shift 0 2 \P3      % mark middle of 1. lens
   \atpin Pinhole1: \shift 0 2 \P4    % mark middle of pinhole
   \atpin SLens2: \shift 0 2 \P5      % mark middle of 2. lens
   \Dtext{\small $f_1$} from P3 to P4 % f_1
   \Dtext{\small $f_2$} from P4 to P5 % f_2
   \atpin BSplit1.                    % second part of beam down
   \oa 5 d
   \Mirror1 {} * R                    % mirror
   \oa 2 r
   \nl\ScrL1 {screen} h               % white screen
\end{circuit}
\end{document}