Gaussian beam interaction with an air-gap Fizeau interferential wedge

Area of Science:

• Optics and Photonics
• Laser Physics
• Interferometry

Background:

• Optical elements like Fizeau wedges are critical in laser resonator design.
• Understanding fringe patterns in optical elements is essential for precise laser control.

Purpose of the Study:

• To develop a plane-wave-expansion approach for calculating fringe patterns in optical wedges.
• To analyze the effects of positive and negative light incidence on fringe patterns.
• To provide experimental verification for the theoretical model.

Main Methods:

• Utilized a plane-wave-expansion approach for theoretical calculations.
• Performed numerical simulations for a high-reflectivity-coating air-gap Fizeau interferential wedge.
• Conducted experimental verification of the simulation results.

Main Results:

• Demonstrated that positive and negative light incidence produce mathematically equivalent fringe patterns.
• Showed that the fringe pattern from positive incidence continues the pattern from negative incidence.
• Validated the model with numerical simulations and experimental data for wedges with specific apex angles and thicknesses.

Conclusions:

• The plane-wave-expansion method accurately predicts fringe patterns in optical wedges.
• The symmetry of fringe patterns under opposing incidences simplifies optical system design.
• The findings are directly applicable to the design of optical elements for laser resonators.