\begin{tikzpicture}
    \tkzSetUpPoint[shape=circle,size=3,color=black,fill=black]
    \tkzSetUpLine[line width=1]
    \tkzInit[xmax=7,ymax=3,xmin=-1,ymin=0]
    \tkzDefPoints{2/0/m1,4/0/m2,1/1.1/a1,1/0/a1x, 2.5/2.0/a2,2.5/0/a2x}
    \tkzDrawSegments(a1x,a1 a2x,a2)
    \tkzAxeXY[ticks=false]

    \tkzDrawArc[R,line width=1pt,color=red](m1,1.5 cm)(0,180)
    \tkzDrawArc[R,line width=1pt](m2,2.5 cm)(0,180)
    \tkzDrawPoints(m1,m2,a1,a2)
    \tkzLabelPoint[above](m1) {$m$}
    \tkzLabelPoint[above](m2) {$\lambda^2 m$}
    \tkzLabelPoint[above](a1) {$m+\iu r$}
    \tkzLabelPoint[above](a2) {$\lambda^2 m+\iu \lambda^2 r$}
    \node[red] at ($(m1)+(1.5,-0.2)$)  {$m+1$};
\end{tikzpicture}
