A cw-laser source transmits low-noise, narrow-linewidth optical power via
an optical fiber to a bias-free electro-optic phase modulator at a remote
site, where an antenna or an RF sensor is located. The RF electrical
signal modulates the phase modulator at the remote site, converting an
electrical signal into an optical signal. The phase-modulated optical
signal is fed back via the optical fiber to an optical filter whose
filter transfer characteristics can be tuned and reconfigured to cancel
the intermodulation distortion terms, particularly the dominant 3.sup.rd
order intermodulation, as well as the 2.sup.nd order. The filtered
optical signal is converted to the RF signal at the photodetector. The
optical filter is used to effectively "linearize" the signal at the
receiver end, rather than at the modulator end.