Reference-free holographic diversity interferometry via iterative measurements for high accuracy phase detection

Area of Science:

• Optical Physics
• Interferometry
• Metrology

Background:

• Conventional reference-free holographic diversity interferometry (RF-HDI) faces accuracy limitations due to insufficient internal reference beam power.
• Existing methods struggle with accurate phase distribution measurement when external reference beams are impractical.

Purpose of the Study:

• To develop an enhanced RF-HDI technique that overcomes accuracy issues in phase distribution measurements.
• To improve the quality and power efficiency of the internally generated reference beam.

Main Methods:

• A novel RF-HDI approach employing iterative measurements and feedback is proposed.
• The method utilizes iterative refinement of phase images to enhance the measurement system's accuracy.
• Wavefront accuracy and optical power efficiency of the internal reference beam were experimentally evaluated.

Main Results:

• The proposed iterative RF-HDI method significantly improves measurement accuracy for phase images, including those with random patterns.
• An internal reference beam with near single plane wave characteristics and higher power efficiency was generated.
• The enhanced RF-HDI demonstrated superior performance compared to conventional RF-HDI.

Conclusions:

• Iterative measurements provide a robust solution to enhance RF-HDI accuracy and internal reference beam quality.
• This advanced RF-HDI technique is applicable to diverse fields requiring high-coherency reference beams, such as optical fiber modal analysis and atmospheric turbulence studies.