SHORT DESCRIPTION

A sensor that employs slow‐light augmentation in an unbalanced Mach–Zehnder
interferometer to significantly boost laser frequency shift sensitivity for precise inertial
measurements.

INVENTORS
• Selim Shahriar*
o Professor of Electrical & Computer Engineering
• David Smith
• Jason Bonacum
• Jinyang Li
• Ruoxi Zhu
• Zifan Zhou
* Principal Investigator
 

NU Tech ID NU 2024-217
IP STATUS
Provisional Patent filed
 

BACKGROUND
Conventional inertial sensors based on ring lasers and standard interferometers face limited sensitivity when detecting minute frequency shifts. High‐finesse cavities and finite laser linewidths constrain performance and elevate costs. These limitations stunt advances in precision inertial measurements necessary for modern navigation and sensing applications.

ABSTRACT
Inertial navigation lies at the heart of many modern technologies, such as space navigation. The performance of such devices is evaluated by their ability in measuring rotation and acceleration rates. A slow-light augmented Mach-Zehnder interferometer (SLAUMZI) can measure frequency shift very precisely. When combined with ring lasers, which translates the motion of the lasers into frequency shift in the lasers, it can achieve superior performance in motion sensing. Thus, we propose an accelerometer-incorporated gyroscope using the SLAUMZI (referred as “the system” later). The system is composed of a ring laser stage, SLAUMZIs and feedback stages. The laser stage includes two ring Raman lasers of which frequency shift is proportional to rotation/acceleration rate. Depending on the application, the frequency shift in these lasers can be magnified (superluminal case) or suppressed (subluminal case) when compared to traditional ring lasers. In either case, the shifted frequency of the lasers is sent to the SLAUMZIs, which produce the slow-light effect via electro-magnetically induced transparency and can measure the frequency shift in a laser by an order of ~10^7 times smaller than what the conventional technique would do. Therefore, the rotation/acceleration rate can be inferred by way of precise frequency shift measurement.

APPLICATIONS
• Gyroscope precision improvement: Enhances angular velocity measurement
accuracy.
• Accelerometer sensitivity enhancement: Delivers refined inertial detection for
motion sensing.
• Inertial navigation systems: Strengthens sensor inputs for advanced navigation.
• Integrated sensor upgrades: Facilitates performance upgrades to existing sensor
platforms.

ADVANTAGES
• Significant sensitivity boost: Achieves up to 22,355-fold enhancement in
frequency shift detection.
• Overcomes laser linewidth constraints: Utilizes slow-light techniques to bypass
traditional sensitivity limits.
• Robust experimental validation: Demonstrates performance improvements in a
simulated operational environment.
• Versatile sensor integration: Applicable across various inertial sensor designs
including gyroscopes and accelerometers.

PUBLICATIONS
• Selim Shahriar et al., A Ring Laser Gyroscope and Accelerometer with Sensitivity
Enhanced by a Slow-light Augmented Unbalanced Mach-Zehnder Interferometer,
arXiv, 2024

KEYWORDS
Ring Laser Gyroscope, Accelerometer, Slow-light, Mach-Zehnder Interferometer,
Frequency Shift Measurement, Inertial Sensing, Electromagnetically Induced
Transparency, Sensor Enhancement