Biomedical subjects

Thijs Klaassen

Publications and source records attributed to Thijs Klaassen.

2 recordsLinked to original sources

PubMed2005

Transverse mode coupling in an optical resonator.

Small-angle scattering due to mirror surface roughness is shown to couple the optical modes and deform the transmission spectra in a frequency-degenerate optical cavity. A simple model based on a random scattering matrix clearly visualizes the mixing and avoided crossings between multiple transverse modes. These effects are visible only in the frequency-domain spectra; cavity ringdown experiments are unaffected by changes in the spatial coherence, as they probe just the intracavity photon lifetime.

Journal Article↗

PubMed2004

Gouy phase of nonparaxial eigenmodes in a folded resonator.

We study the effect of nonparaxiality in a folded resonator by accurate measurements of the Gouy phase as a function of the mode number for mode numbers up to 1500. Our experimental method is based on tuning the resonator close to a frequency-degenerate point. The Gouy phase shows a nonparaxial behavior that is much stronger in the folding plane than in the perpendicular plane. Agreement with ray-tracing simulations is established, and a link with aberration theory is made.

Journal Article↗