Biomedical subjects

Gijs van Soest

Publications and source records attributed to Gijs van Soest.

2 recordsLinked to original sources

PubMed2002

Speckle experiments in random lasers.

We present measurements of speckle in a random laser. We analyze its first-order statistics and show that, contrary to what might be expected for passive systems, analyses of the intensity distribution P(I) and the speckle spot size do provide information about light transport inside the system. P(I) is used to determine the degree to which an incident probe is amplified by the random laser. The shrinking speckle spot size reflects the change in path length distribution P(Lambda); we deduce that the average path length in the studied random laser is two times longer above threshold than in a passive diffusive system.

Journal Article↗

PubMed2002

Beta factor in a random laser.

We develop a definition for the beta factor, the fraction of spontaneous emission that seeds the laser process, for a random laser. With the wavelength-dependence of the gain (and potentially scattering) being the only possible criterion in the competition between gain and loss, our concept of beta is based on the spectral properties of the spontaneous emission and laser light. We find beta approximately equal to 0.1. We discuss the apparent similarities and differences between the beta for a cavity and a random laser.

Journal Article↗