Quasimonochromatic white light fringe interferometer.

Area of Science:

• Optics and Photonics
• Metrology

Background:

• Accurate determination of zero path difference is crucial for interferometric measurements.
• Quasimonochromatic light sources offer potential for enhanced fringe visibility and resolution.

Purpose of the Study:

• To assess the suitability of laser diodes and high-power LEDs for zero path difference determination.
• To compare theoretical fringe visibility with experimental results in a Michelson interferometer.

Main Methods:

• Theoretical determination of fringe visibility curves for various light sources.
• Experimental validation using a Michelson interferometer with a 25-m path length.
• Analysis of fringe visibility and achieved resolution.

Main Results:

• A resolution of 2-3 micrometers was achieved using multimode laser diodes and a laser diode operated as an LED.
• Experimental results align with theoretical predictions for fringe visibility.
• The achieved resolution is sufficient for survey baseline calibration.

Conclusions:

• Multimode laser diodes and laser diodes operated as LEDs are suitable for zero path difference determination.
• The study demonstrates a practical method for high-resolution interferometric measurements.
• The findings support the use of these light sources for precise metrology applications.