The ring laser gyro (RLG) IS JUST ABOUT AS DIFFERENT FROM A CONVENTIONAL GYRO AS IT POSSIBLE TO GET .THE rlg OPERATES ON THE PRINCIPLE of the relativemovement of two beams of laser light, whereas a conventional gyro operates on the principla of stored mechanical energy (inertial). RLGs are a solid state alternative to the conventionalrate integrating gyro.
THE CONSTRUCTION of a triangular ring laser gyro is shown at figure 13.1 shows a cross section through the sensitive plane of the RLG ,thesensitive axis passes perpendicularly through the page . square RLG are also manufactured ,the principle of operation is much the same.
the RLG is formed from a solid block of cer vit(glass/ceramic ) material which is used because it has a very ñow temperatura co- efficient . it does not distort with age , which would degrade the accuracy and perhaps destroythe gas right seal necessary to contain the helium and neon gases .
Channels are drilled very accurately in the block to from two triangular laser paths which are filled witha low pressure helium /neon mixture.
Two anodes and a common cathode are used to created electrical discharges within the gases which cause the channels to act as gain tubesproducing laser beams . these beams travel in opposite directions around the triangular block.
At each of the three corners of the block are flat mirrors which reflect thelaser beams into the next channel .two of these mirrors (B and C at figure 13-1 ) are mavable and are controlled by piezo electric actuators operating in a closed loop system toadjust the optical path length to within precise limits, and so to correct for the small expansións/contractions of the block with changing temperatures within the permitted...