No abstract

No abstract

The hole diffusion length, hole lifetime, hole mobility, and hole equilibrium concentration in epitaxial heavily phosphom-doped silicon have been measured by a combination of steady-state and transient techniques. Steady state measurements were performed on bipolar transistors in which the base was epitaxially grown. The transient measurement relied on the observation of the decay of the photoluminescence radiation after laser excitation. Significant findings are: 1) the hole mobility is about a factor of two larger in heavily doped n-type silicon than in p-type silicon; 2) the apparent bandgap narrowing is smaller than previously thought, with a value of about 90 meV at a doping level of 10'' cm-'.

We observe a polarization instability in circularly symmetric vertical-cavity surface-emitting lasers. A relatively long time, 3–5 ns, is required to establish a dominant polarization state. Under high-speed digital modulation this leads to strong enhancement, 20–30 dB, in polarization resolved low-frequency relative intensity noise. This polarization instability is accurately described by a simple rate-equation model. A similar increase in relative intensity noise, under dc bias, is caused by energy partition between orthogonally polarized modes.

No abstract

No abstract

No abstract

No abstract