  An analysis is given for the Fabry-Perot cavity having a combination of
dissipative and dispersive optomechanical coupling. It is established that the
combined coupling leads to optical rigidity. At the same time, this rigidity
appears in systems with the combined coupling on the resonant pump, which is
not typical for pure dispersive and dissipative couplings. A proposal is made
to use this system to detect small signal forces with better sensitivity than
SQL. It is also demonstrated that this optomechanical system can create
ponderomotive squeezing with controllable parameters over a wider range than
ponderomotive squeezing using dispersive coupling.
