Optimum Biasing of VCSEL Diodes for All-Optical Up-Conversion of OFDM Signals

Nonlinear behavior of vertical-cavity surface-emitting laser (VCSEL) diodes is exploited to perform all-optical up-conversion by second- and third-order mixing. We investigate and explain conditions for optimum frequency mixing with a common WLAN IEEE 802.11a signal. Then, we apply these findings to the transmission of an ultra-wideband (UWB) multiband-OFDM ECMA-368 signal over a fiber-optic link. We demonstrate direct modulation with the UWB signal up to 10.3 GHz and perform up-conversion to frequencies as high as 16 GHz, far beyond the cutoff frequency of the VCSEL diode.