Abstract
The wave number of transverse spatial structures in broad-area vertical-cavity surface-emitting lasers (VCSELs) is controlled via frequency-selective feedback from an external self-imaging cavity in a broad range of wave numbers and emission frequencies. The selected states follow the dispersion curves of the free-running laser. A control range of about 2.5 µm−1 in spatial frequency space and 2.5 nm in emission wavelength was obtained for square VCSELs and of about 3 µm−1 and 8 nm for circular VCSELs having a different dispersion curve. By spatial filtering in Fourier space, the shape of the structures can also be controlled to some extent. It is argued that the feedback techniques are useful to 'probe' emission states of the free-running laser.
| Original language | English |
|---|---|
| Article number | 055101 |
| Number of pages | 9 |
| Journal | Journal of Physics D: Applied Physics |
| Volume | 42 |
| Issue number | 5 |
| DOIs | |
| Publication status | Published - 7 Mar 2009 |
Keywords
- semiconductor lasers
- laser diodes
- resonators
- cavities
- amplifiers
- arrays
- beam characteristics
- beam intensity
- spatial pattern formation Optics
- quantum optics
- lasers