begin{pspicture}[showgrid](0,0)(3,3)
pnodes(0,0){Laser}(1,0){M1}(2,3){M2}(3,1.5){End}
begin{optexp}
    optsource[innerlabel](Laser)(M1){Laser}
    mirror[compname=M1](Laser)(M1)(M2){M1}
    lens[position=0.3] (M1)(M2){L1}
    mirror[compname=M2](M1)(M2)(End){M2}
    drawbeam (Laser){M1}{M2}(End)
end{optexp}
end{pspicture}