Related Experiment Video
Updated: Jul 6, 2026
09:48
Fiber Optic Distributed Sensors for High-resolution Temperature Field Mapping
Published on: November 7, 2016
Fiber distributed-feedback lasers used as acoustic sensors in air
S W Løvseth1, J T Kringlebotn, E Rønnekleiv
1Department of Physical Electronics, Norwegian University of Science and Technology, N-7034 Trondheim, Norway. swl@fysel.ntnu.no
Applied Optics
|March 8, 2008
Summary
Acoustic signals shift fiber distributed-feedback (DFB) laser frequencies, primarily due to air temperature changes at low frequencies and air pressure at high frequencies. Sensitivity varies with acoustic frequency, impacting laser performance.
Area of Science:
- Optoelectronics
- Acoustics
- Fiber Optics
Background:
- Fiber distributed-feedback (DFB) lasers are sensitive to environmental factors.
- Understanding acoustic signal interference is crucial for stable laser operation.
Purpose of the Study:
- To investigate the acoustic signal sensitivity of fiber DFB lasers in air.
- To differentiate between temperature and pressure contributions to laser frequency shifts.
- To experimentally validate theoretical predictions.
Main Methods:
- Theoretical modeling of laser frequency shifts caused by acoustic signals.
- Experimental measurement of acoustically induced frequency shifts in two fiber DFB lasers.
- Analysis of frequency dependence on temperature and pressure effects.
Main Results:
- Dominant contributions to laser frequency shift are adiabatic temperature shifts (low frequencies) and pressure (high frequencies).
- Transition frequency between dominant effects ranges from 5 to 20 kHz.
- Measured sensitivities varied from 0.61 MHz/Pa at 100 Hz to 0.34 kHz/Pa at 15 kHz.
Conclusions:
- Acoustic signals significantly impact fiber DFB laser frequency.
- Frequency shift mechanisms are frequency-dependent, influenced by air temperature and pressure.
- Results provide critical data for designing robust fiber laser systems.
