A photonic up-converter for a WDM radio-over-fiber system using cross-absorption modulation in an EAM

A photonic frequency up-converter with a wide wavelength bandwidth is demonstrated. The up-converter is based on wavelength conversion by cross-absorption modulation in an electroabsorption modulator. A two-tone measurement is performed to investigate the linearity of the proposed up-converter. Moreover, its dependence on the wavelength and bias voltage are found to be suitable for wavelength-division-multiplexing-based radio-over-fiber application. The proposed up-converter has a spurious free dynamic range larger than 73.8 dB/spl middot/Hz /sup 2/3/ throughout the 30-nm range of the local oscillator wavelength. Also, the up-converted signal at 26 GHz has a phase noise of -76.8 dBc/Hz at a 10-kHz offset.