High-sensitive multi-pass imaging interferometry of a gas/plasma jet

Area of Science:

• Physics
• Optical Engineering

Background:

• Optical interferometry is crucial for diagnosing transparent media like gas/plasma jets.
• Standard single-pass setups often lack the sensitivity required for weakly refractive materials.

Purpose of the Study:

• To enhance the sensitivity of optical interferometry for diagnosing gas/plasma jet density.
• To develop and evaluate multi-pass probing techniques for improved measurement accuracy.

Main Methods:

• Modified Michelson interferometer designs were employed.
• Multi-pass and multi-angle propagation of the probing beam through the inhomogeneity were utilized.
• Comparison with standard single-pass Mach-Zehnder setups was performed.

Main Results:

• Multi-pass interferometry setups demonstrated significantly increased sensitivity.
• Sensitivity enhancement of up to 8 times was achieved compared to single-pass methods.
• The technique proved effective for transparent, axially symmetrical gas/plasma jets.

Conclusions:

• Multi-pass optical interferometry offers a substantial improvement in sensitivity for diagnosing weakly refractive gas/plasma jets.
• This technique provides a viable solution for high-sensitivity measurements in transparent media.
• The modified Michelson interferometer is a promising tool for advanced plasma diagnostics.