Lock-in reduction technique for fiber-optic ring laser gyros.

Area of Science:

• Optics and Photonics
• Fiber Optic Sensors
• Inertial Navigation

Background:

• Brillouin fiber-optic gyroscopes (BFOGs) are crucial for high-precision rotation sensing.
• Frequency locking, a phenomenon that limits BFOG performance, occurs when the beat frequency approaches zero.
• Existing methods to mitigate frequency locking often add complexity or compromise system performance.

Purpose of the Study:

• To demonstrate a novel method for suppressing frequency locking in Brillouin fiber-optic gyros.
• To achieve an all-fiber system with optical reciprocity.
• To experimentally validate the effectiveness of the proposed technique.

Main Methods:

• Implementation of a push-pull phase modulation scheme within the fiber optic ring cavity.
• Utilizing an in-line modulation approach to maintain optical reciprocity.
• Experimental measurement of the lock-in range width before and after applying the modulation.

Main Results:

• Successful suppression of frequency locking was achieved.
• The implemented system demonstrated all-fiber construction with optical reciprocity.
• A tenfold reduction in the width of the lock-in range was experimentally observed.

Conclusions:

• The push-pull phase modulation technique effectively suppresses frequency locking in Brillouin fiber-optic gyros.
• This method enables a practical all-fiber solution for high-performance rotation sensing.
• The demonstrated reduction in lock-in range width significantly enhances the operational range and accuracy of BFOGs.