VCSELs are a type of semiconductor laser. They are similar to LEDs in that the light is emitted from the surface of the wafer or chip. With conventional edge-emitting lasers, the light is emitted from the edge of the chip, requiring that the wafer be sawn or cleaved, and the chip packaged, before testing.
In addition to the manufacturing and associated cost advantages, VCSELs possess performance advantages over both conventional LEDs and edge-emitting lasers.
- Low threshold currents for high efficiency and low power consumption
- Surface-normal emission, low divergence and circular output beam, ease of coupling, and simple optics.
- Easily scaleable to one- or two-dimensional arrays
- Very high speed, with rise and fall times of 100 picoseconds or less
- Controlled single transversal mode and polarization
- 4~5X better wavelength stability with temperature than conventional edge emitting lasers
- Manufacturing flexibility
- Package flexibility
|Power consumption (e.g. 1mW optical power)||2-3mW||20mW||3-5mW|
|Beam quality/ease of coupling to optics||Best, round low divergence||Fair, Asymmetric||Poor, Very wide divergence (Lambertian)|
|Speed||10Gbps||1 Gbps||0.1 Gbps|
|Speckle||Low in an array||High||Low|