Interferometry based technique for intensity profile measurements of far IR beams

Area of Science:

• Optics and Photonics
• Laser Technology
• Materials Science

Background:

• Accurate measurement of far-infrared (far-IR) beam intensity profiles is crucial for industrial applications.
• Existing methods may have limitations in terms of accessibility, scalability, or spatial resolution.
• Industrial processes increasingly utilize powerful far-IR lasers, necessitating precise beam characterization.

Purpose of the Study:

• To introduce a novel, accessible method for measuring the intensity profile of far-IR beams.
• To demonstrate the feasibility of using optical thickness variations in heated fused silica for beam profiling.
• To establish a scalable measurement technique suitable for industrial laser systems.

Main Methods:

• The method relies on measuring non-stationary variations in the optical thickness of a fused-silica plate.
• The fused-silica plate is heated by the far-IR radiation whose intensity profile is being measured.
• Optical thickness changes are monitored using a reflecting interferometer setup.
• A purpose-made experimental setup allows for measurements of beams up to 60 mm in aperture with 1 mm spatial resolution.

Main Results:

• The developed method successfully measures the intensity profile of far-IR beams.
• The technique utilizes the relationship between laser heating and changes in optical thickness.
• The experimental setup demonstrates good spatial resolution and aperture handling capabilities.
• The method proved to be accessible, utilizing readily available technologies.

Conclusions:

• This novel method provides an accessible and scalable approach for characterizing far-IR beam intensity profiles.
• The technique is well-suited for measurements of beams from powerful industrial far-IR lasers.
• The use of fused silica and interferometry offers a practical solution for beam profiling in demanding industrial environments.