A 30 dB gain with multi-GHz modulation bandwidth is obtained in an opt
ically pumped vertical cavity Fabry-Perot structure. This device may b
e called a vertical cavity amplifying photonic switch (VCAPS). The amp
lification configuration has been used for a direct measurement of the
carrier induced refractive index change over the absorption as well a
s the gain regime. (C) 1994 American Institute of Physics.