Is the VCSEL output polarization stable?
Yes. Unlike an 850nm VCSEL, where the polarization direction can be random and change with drive current, the Firecomms visible VCSEL has a well defined polarization direction which remains invariant with drive current. The polarization direction is fixed as a consequence of the (AlGaIn)P semiconductor materials that are at the heart of the device. When these materials are grown epitaxially the materials have a natural tendency to spontaneously order in a preferred crystal direction. This anisotropy results in natural polarization selectivity.
