Related Experiment Video
Updated: Mar 13, 2026
11:08
Fabrication And Characterization Of Photonic Crystal Slow Light Waveguides And Cavities
Published on: November 30, 2012
19.6K
Free-space coupling efficiency in a high-Q deformed optical microcavity.
Optics Letters
|October 18, 2016
Summary
Researchers quantified free-space coupling efficiency in deformed microcavities using stimulated Raman scattering. Efficiencies reached 30%, showing robustness to beam translation, crucial for microcavity applications.
Area of Science:
- Optics and Photonics
- Materials Science
Background:
- Whispering gallery modes (WGMs) in microcavities are vital for photonics.
- Free-space coupling is promising but quantifying efficiency is difficult due to spectral complexities.
Purpose of the Study:
- To experimentally determine the free-space coupling efficiency in deformed microcavities.
- To investigate the angular dependence and spatial stability of this coupling efficiency.
Main Methods:
- Utilized stimulated Raman scattering (SRS) threshold measurements in a deformed microcavity.
- Analyzed the dependence of coupling efficiency on incident laser angle.
- Assessed efficiency variations with horizontal and vertical beam translation.
Main Results:
- Achieved a free-space coupling efficiency of up to 30%.
- Observed coupling efficiency dependence on incident angle, aligning with theoretical mode field predictions.
- Demonstrated sustained high coupling efficiencies despite beam displacements of several micrometers.
Conclusions:
- Stimulated Raman scattering threshold provides a reliable method for quantifying free-space coupling efficiency.
- The free-space coupling technique is robust and efficient for exciting WGMs in microcavities.
- Results confirm the viability of free-space coupling for practical microphotonic device applications.
