  A photonic-assisted multiple radio frequency (RF) measurement approach based
on stimulated Brillouin scattering (SBS) and frequency-to-time mapping with
high accuracy and high-frequency resolution is reported. A two-tone signal is
single-sideband (SSB) modulated on an optical carrier via a dual-parallel
Mach-Zehnder modulator to construct one SBS gain and two SBS losses for SBS
gain bandwidth reduction. The unknown RF signal is also SSB modulated on a
carrier that has been modulated by a sweep signal, thus the unknown RF signal
is converted to a sweep optical signal along with the sweep optical carrier.
The bandwidth-reduced SBS gain spectrum is detected by the sweep optical
signals at different specific time, mapping the RF frequencies to the time
domain. An experiment is performed. RF frequencies from 0.3 to 7.6 GHz are
simultaneously measured with a root mean square error of less than 1 MHz. In
addition, the frequency resolution of the measurement can be much lower than 10
MHz, which is now the best result in the RF frequency measurement methods
employing the SBS effect.
