Optical mode interaction with the mechanical mode is gravitationally induced while mechanical mode interaction with the optical mode is electromagnetically induced and both are optomechanical coupling. The EM force (Coulombs or Lorentz force) is the charge domain while the gravity force is the mass domain. Both the mass domain gravitational force and the charge domain EM force affect light interaction. Both gravity and EM are conservative forces, and their interrelationship in optomechanical coupling is new area of research.