Beam-quality measurements using a spatial light modulator.

Area of Science:

• Optics and Photonics
• Laser Physics
• Metrology

Background:

• Accurate measurement of laser beam quality is crucial for many applications.
• Traditional methods for determining the beam propagation ratio (M²) can be time-consuming and complex.
• Existing techniques often require moving optical components or prior knowledge of beam characteristics.

Purpose of the Study:

• To introduce a novel, fast, and user-friendly technique for measuring the M² of laser beams.
• To eliminate the need for physical scanning along the propagation axis in M² measurements.
• To demonstrate a method that does not require prior information about the laser beam or moving optical parts.

Main Methods:

• Utilizing a spatial light modulator (SLM) to digitally simulate free-space light propagation.
• Implementing two distinct approaches based on digital simulation via SLM.
• Performing measurements without requiring knowledge of the laser beam's initial parameters.

Main Results:

• The developed technique provides a fast and easy method for M² measurement.
• Two SLM-based approaches were successfully demonstrated.
• The absence of moving optical components and pre-existing beam information was confirmed.
• Experimental results showed excellent agreement with theoretical predictions, validating the technique's accuracy.

Conclusions:

• The proposed technique offers an accurate and efficient alternative for laser beam quality assessment.
• Digital simulation of light propagation using SLMs simplifies and accelerates M² measurements.
• This method enhances laser metrology by removing hardware complexity and prior data requirements.