Experiment Laser Gyroscope System

The Laser gyroscope is one of the most fascinating applications of the Laser. It is a high-precision absolute rotation sensor. This lab covers both the adjustment of the experimental setup and the principles of measurement.

Topics covered:
- He-Ne ring laser
- Modes, Single-mode Etalon
- Interference between the 2 counter-propagating rays
- Sagnac effect
- Calibration and calibration factor
- Detection threshold
- Dynamic measurement

Principles and objectives:
This educational set allows students to learn how to use and adjust optical and mechanical elements to align such a system. In the ring, the laser beams propagate in both directions and interfere. The signals are detected, amplified, transmitted to a comparator, and then a TTL signal is generated.
When this laser is rotated, the clockwise and counterclockwise optical paths are no longer identical, and a beat frequency can be measured.
After aligning the setup and obtaining the interferences, the system needs to be calibrated. To do this, the rotation table is driven at a series of increasing angular speeds. The slope of the resulting linear relationship gives the calibration factor.
When the speed scan is carried out at low values, it is possible to access the detection threshold value, which corresponds to the disappearance of the interferences.

Composition:
▪ 1 gyroscope platform with He-Ne annular laser (laser tube, mirrors, monomode etalon)
▪ 1 photodetector
▪ 1 amplifier and comparator housing for detection signals
▪ 1 power supply for He-Ne Laser
▪ 1 rotation system for the platform
▪ 1 controller for rotation with Joy-Stick
▪ 1 adjustment laser for resonator alignment
▪ 1 frequency meter
▪ 1 optical cleaning kit
▪ 1 experiments manual (in English)