The angular reflectivity properties of a Fabry-Perot were used to perform spatial filtering in the near field. A series of experiments was performed using an external Fabry-Perot and a top emitting VCSEL with a wavelength of 850 nm. The 7.5 μm-diameter VCSEL lased in several spatial modes at currents slightly above threshold when a conventional mirror was used. However, by employing the Fabry-Perot filter and tuning its response to favor the angular radiation pattern of the fundamental mode, the VCSEL was able to maintain single-mode operation over the entire current range. Studies of the filtering properties of this optical cavity indicate that high modal discrimination should be possible for VCSEL apertures up to 20 μm in diameter.
|Original language||English (US)|
|Number of pages||1|
|State||Published - Jan 1 1998|
|Event||Proceedings of the 1998 International Symposium on Information Theory, CLEO/EUROPE'98 - Glasgow, Scotland|
Duration: Sep 14 1998 → Sep 18 1998
|Other||Proceedings of the 1998 International Symposium on Information Theory, CLEO/EUROPE'98|
|Period||9/14/98 → 9/18/98|