Ring laser gyro with optically independent semiconductor ring lasers

A method of driving a ring laser gyro comprising:

• operating a plurality of semiconductor ring lasers, including at least first and second semiconductor ring lasers, at constant current, said first and second semiconductor ring lasers being optically independent from each other, and each of said first and second ring lasers having counterpropagating laser beams which generate a beat frequency in response to angular velocity, wherein a change in beat frequency with respect to a change in angular velocity of said first semiconductor ring laser is opposite to that of said second semiconductor ring laser, wherein an angular velocity of rotation of said ring laser gyro is detected by a signal representing a difference between a first beat frequency generated by said first semiconductor ring laser and a second beat frequency generated by a second semiconductor ring laser;
• and
• detecting a voltage change at electric terminals which are connected to each of said first and second semiconductor ring lasers.

A method of driving a ring laser gyro comprising:

• operating a plurality of semiconductor ring lasers, including at least first and second semiconductor ring lasers, at constant voltage, said first and second semiconductor ring lasers being optically independent from each other, and each of said first and second ring lasers having counterpropagating laser beams which generate a beat frequency in response to angular velocity, wherein a change in beat frequency with respect to a change in angular velocity of said first semiconductor ring laser is opposite to that of said second semiconductor ring laser, wherein an angular velocity of rotation of said ring laser gyro is detected by a signal representing a difference between a first beat frequency generated by said first semiconductor ring laser and a second beat frequency generated by a second semiconductor ring laser;
• and
• detecting a drive current change at electric terminals which are connected to each of said first and second semiconductor ring lasers.

A method of processing a signal from a ring laser gyro comprising:

• operating a plurality of semiconductor ring lasers, including at least first and second semiconductor ring lasers, said first and second semiconductor ring lasers being optically independent from each other, and each of said first and second ring lasers having counterpropagating laser beams which generate a beat frequency in response to angular velocity, wherein a change in beat frequency with respect to a change in angular velocity of said first semiconductor ring laser is opposite to that of said second semiconductor ring laser, wherein an angular velocity of rotation of said ring laser gyro is detected by a signal representing a difference between a first beat frequency generated by said first semiconductor ring laser and a second beat frequency generated by a second semiconductor ring laser;
• and
• detecting angular velocity and rotational direction of said ring laser gyro on the basis of an impedance change in said first and second semiconductor ring lasers.