  Coherent Ising machine (CIM) implemented by degenerate optical parametric
oscillator (DOPO) networks can solve some combinatorial optimization problems.
However, when the network structure has a certain type of symmetry, optimal
solutions are not always detected since the search process may be trapped by
local minima. In addition, a uniform pump rate for DOPOs in the conventional
operation cannot overcome this problem. In this paper proposes a method to
avoid trapping of the local minima by applying a control input in a pump rate
of an appropriate node. This controller breaks the symmetrical property and
causes to change the bifurcation structure temporarily, then it guides
transient responses into the global minima. We show several numerical
simulation results.
