  We study the phase diagram of $\nu_e=7/3$ state in the $N=1$ Landau level in
the presence of band mass anisotropy. Using density matrix renormalization
group on an infinite cylinder geometry, we find a continuous transition from
the topologically ordered Laughlin fractional quantum Hall state to a stripe
phase with a period of approximately five and a half magnetic lengths. The
transition is driven by the condensation of the magnetoroton mode which becomes
gapless at the critical point. We interpret the transition within the
composite-boson theory as the onset of stripe order in a superfluid background,
resulting from the roton mode going soft.
