A ring-laser gyroscope , comprising: a first optical pump configured to generate a first pumped beam ; a second optical pump configured to generate a second pumped beam ; an optical ring resonator configured to generate, in response to the first pumped beam, a first back-scattered Stimulated Brillouin Scattered beam propagating in a direction opposite to a direction in which the first pumped beam is propagating, and to generate, in response to the second pumped beam, a second back-scattered Stimulated Brillouin Scattered beam propagating in a direction opposite to a direction in which the second pumped beam is propagating; characterized by : a switch having a first state in which the switch is configured to cause the first and second pumped beams to propagate in the optical ring resonator in first and second directions, respectively, and having a second state in which the switch is configured to cause the first and second pumped beams to propagate in the optical ring resonator in the second and first directions, respectively; and a detector coupled to the optical ring resonator and configured to determine a first optical beat signal in response to the first and second back-scattered Stimulated Brillouin Scattered beams while the switch has the first state, and to determine a second optical beat signal in response to the first and second back-scattered Stimulated Brillouin Scattered beams while the switch has the second state. a first optical pump configured to generate a first pumped beam ; a second optical pump configured to generate a second pumped beam ; an optical ring resonator configured to generate, in response to the first pumped beam, a first back-scattered Stimulated Brillouin Scattered beam propagating in a direction opposite to a direction in which the first pumped beam is propagating, and to generate, in response to the second pumped beam, a second back-scattered Stimulated Brillouin Scattered beam propagating in a direction opposite to a direction in which the second pumped beam is propagating; characterized by : a switch having a first state in which the switch is configured to cause the first and second pumped beams to propagate in the optical ring resonator in first and second directions, respectively, and having a second state in which the switch is configured to cause the first and second pumped beams to propagate in the optical ring resonator in the second and first directions, respectively; and a detector coupled to the optical ring resonator and configured to determine a first optical beat signal in response to the first and second back-scattered Stimulated Brillouin Scattered beams while the switch has the first state, and to determine a second optical beat signal in response to the first and second back-scattered Stimulated Brillouin Scattered beams while the switch has the second state. to determine a first optical beat signal in response to the first and second back-scattered Stimulated Brillouin Scattered beams while the switch has the first state, and to determine a second optical beat signal in response to the first and second back-scattered Stimulated Brillouin Scattered beams while the switch has the second state. <EOS>