Microfabricated sensor device for CW and pulsed laser power measurements

Area of Science:

• Optics and Photonics
• Sensor Technology
• Metrology

Background:

• On-line measurement is a key trend in laser-based applications.
• Accurate laser power measurement is crucial for various scientific and industrial fields.
• Existing methods may have limitations in precision or applicability to different laser modes.

Purpose of the Study:

• To present a fiber-integrated force sensor for simultaneous radiometric heat and radiation force sensing.
• To enable on-line laser power measurement for both continuous wave (CW) and pulsed laser modes.
• To evaluate the sensor's performance, including non-linearity error and measurement uncertainty.

Main Methods:

• Fabrication of a fiber-integrated force sensor using standard microfabrication.
• Utilizing a Fabry-Perot interferometer to measure movable mirror displacement for laser intensity determination.
• Simultaneous sensing of laser radiometric heat and radiation force.
• Performance evaluation under ambient and quasi-vacuum conditions.

Main Results:

• Achieved a non-linearity error of 0.02% and measurement uncertainty of 2.06% in quasi-vacuum for CW lasers.
• Demonstrated a noise floor of 46.4 μW/Hz^1/2 and a minimum detection limit of 0.125 mW for CW lasers.
• Attained a non-linearity error of 0.37% and measurement uncertainty of 2.08% for pulsed lasers, with a noise floor of 1.3 μJ/Hz^1/2 and a minimum detection limit of 3 μJ.

Conclusions:

• The developed fiber-integrated force sensor enables accurate on-line laser power measurement for both CW and pulsed modes.
• The sensor exhibits high precision and low detection limits, suitable for demanding laser applications.
• The device's performance in quasi-vacuum conditions highlights its potential for precise radiometric measurements.