The laser gyro

One of the most dramatic recent developments in optical technology is the laser gyro, which combines the properties of the optical oscillator, the laser, and general relativity to produce an integrating rate gyroscope. This gyro measures rotation in inertial space, but does not use a spinning mass as conventional gyros do. Because of the absence of spinning mass, the gyro's performance is not affected by accelerations; and it can sense very high rates with great accuracy. Other important advantages of the laser gyro are lack of special cooling, low power consumption, and simplicity of construction.