Related Experiment Video
Updated: Mar 11, 2026
09:03
A Silicon-tipped Fiber-optic Sensing Platform with High Resolution and Fast Response
Published on: January 7, 2019
7.7K
Development of plasma bolometers using fiber-optic temperature sensors
M L Reinke1, M Han2, G Liu2
1Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
The Review of Scientific Instruments
|December 3, 2016
Summary
A new fiber-optic bolometer offers EMI immunity for plasma diagnostics in fusion reactors. This novel sensor shows promise for future applications, despite initial lower sensitivity compared to traditional resistive bolometers.
Area of Science:
- Plasma physics
- Fusion energy research
- Optical sensing technologies
Background:
- Radiated power measurements are crucial for plasma exhaust studies and future fusion reactors.
- Traditional resistive bolometers face limitations due to electromagnetic interference (EMI).
Purpose of the Study:
- To introduce and test a novel fiber-optic bolometer concept for plasma diagnostics.
- To evaluate its performance characteristics, including sensitivity and EMI immunity.
Main Methods:
- A silicon pillar on a fiber-optic cable forms a Fabry-Pérot cavity, detecting temperature changes via optical path length shifts.
- The sensor's performance was compared to resistive bolometers using a modulated laser to estimate noise equivalent power density (NEPD).
Main Results:
- The fiber-optic bolometer demonstrated immunity to EMI and a time constant of ~150 ms.
- Initial tests showed an NEPD of 5-10 W/m², compared to resistive bolometers' <0.5 W/m² in labs, which can degrade in tokamak environments.
Conclusions:
- The fiber-optic bolometer is a promising alternative to resistive sensors, especially in EMI-prone environments.
- Further improvements, such as reducing pillar height and adding metallic coatings, can enhance its signal-to-noise ratio for fusion applications.
