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Limits imposed by nonlinear coupling on rotation sensitivity of a semiconductor ring laser gyroscope
Applied Optics
|July 14, 2016
Summary
The sensitivity of semiconductor ring laser gyros is limited by a high lock-in threshold. Nonlinear coupling between modes, caused by rotation-induced gratings, restricts gyro sensitivity to 10^8 deg/h.
Area of Science:
- Photonics
- Optical Engineering
- Solid-State Physics
Background:
- Monolithically integrated semiconductor ring laser gyros are crucial for inertial navigation.
- Their practical application is hindered by a high lock-in threshold, limiting sensitivity.
Purpose of the Study:
- To investigate and quantify the factors limiting the sensitivity of semiconductor ring laser gyros.
- To analyze the lock-in threshold using theoretical models.
Main Methods:
- Perturbation theory was employed to analyze the lock-in threshold.
- Coupled mode theory was used to model the nonlinear coupling between countertraveling modes.
Main Results:
- The lock-in threshold was calculated to be 10^8 degrees per hour.
- Nonlinear coupling between countertraveling modes was identified as the primary limitation.
- This coupling results from mode backreflection by rotation-induced index gratings.
Conclusions:
- Gyro sensitivity is fundamentally limited by nonlinear mode coupling.
- The lock-in threshold is directly proportional to coupling strength and mode overlap with index perturbations.
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