Setting up and studying a He-Ne laser cavity

Study of the operating principle of a He-Ne laser cavity and the properties of its radiation. Topics covered: - Adjustment and alignment of a laser cavity via an external mirror - Autocollimation method, resonant cavity, Laser effect - Study of the stability conditions of the cavity. Measurement of emission power based on cavity length - Study of geometric properties: spatial profile, Gaussian beam, waist, Rayleigh length (Zr), divergence - Study of the spectra of Helium-Neon gas and laser radiation, monochromaticity, luminescence - Study of polarization, measurement of the polarization rate. Observation of different transverse modes Principles and objectives: The kit used consists of a tube filled with He-Ne gas. A fixed mirror, with a radius of curvature R1 = 60 cm and reflectivity ≈ 99.99%, is sealed inside this tube. Opposite this mirror, a Brewster window allows the polarization of the ouExperimentut beam. To close the laser cavity, a second (external) mirror is used. Its radius of curvature is R2 = 45 cm (a 100 cm mirror is available as an option, ref.205115) and its reflectivity is close to 99%. The horizontality and verticality of this mirror can be adjusted using 2 micrometer screws. The experiments to be carried out are as follows: Experiment 1: Adjustment of the cavity to obtain the laser effect Experiment 2: Study of the stability conditions of the cavity Experiment 3: Study of transverse modes Experiment 4: Study of the divergence of the laser beam Experiment 5: Focusing by a lens and study of the geometric properties of the laser beam Experiment 6: Study of the polarization of the laser beam Experiment 7: Study of the spectra of helium-neon gas and laser radiation This product was developed in collaboration with the CY TECH school in Cergy.

Composition:
▪ 1 He-Ne Plasma tube with support and laboratory power supply
▪ 1 cavity output mirror R2 = 45 with precision X-Y adjustable mount (ref.205101)
▪ 1 set of experiment instructions

To be completed with:
A bench and clamps