Method for determining full-field absolute phases in the common-path heterodyne interferometer with an electro-optic...

Area of Science:

• Optics and Photonics
• Signal Processing
• Metrology

Background:

• Electro-optic modulators are crucial components in optical systems.
• Accurate phase measurement is essential for various applications, including interferometry and optical sensing.
• Traditional phase measurement techniques can be complex or limited in scope.

Purpose of the Study:

• To develop a novel algorithm for determining the absolute phase from segmented interference signals generated by electro-optic modulators.
• To enable full-field absolute phase measurements by applying the algorithm to all pixels.
• To validate the proposed method for practical applications.

Main Methods:

• Applying a sawtooth voltage signal below the half-wave voltage to an electro-optic modulator.
• Developing an algorithm to reconstruct continuous sinusoidal waves from segmented interference signals.
• Calculating initial phase, subtracting modulator characteristic phase to obtain absolute phase.
• Extending the technique for pixel-wise application to achieve full-field measurements.

Main Results:

• Interference signals were successfully modified into continuous sinusoidal waves.
• Initial phase determination was achieved with high accuracy.
• Absolute phase was successfully obtained by accounting for the modulator's characteristic phase.
• The method demonstrated the capability for full-field absolute phase measurements.

Conclusions:

• The proposed algorithm effectively determines absolute phase from segmented interference signals of electro-optic modulators.
• This technique offers a robust and accurate method for full-field absolute phase measurements.
• The demonstrated validity suggests potential for widespread use in optical metrology and sensing.