We report a new design of differential phase-shift keying (DPSK) receivers which utilize a single demodulator to receive
polarization division multiplexed signals. More than 20 dB extinction-ratio can be achieved by optimizing the phase
detuning with a polarization controller in the receiver. Experimental demonstrations using 20 Gb/s polarization
multiplexed DPSK signals and 2<sup>15</sup>-1 pseudorandom binary sequence are conducted to show the performance of the
proposed receiver. After 60 km of optical fiber transmission, the receiver has less than 3 dB power penalty at bit-error
rate (BER) of 10<sup>-9</sup>.
Microwave signal generation and processing such as frequency conversion are proposed and experimentally
demonstrated based on stimulated Brillouin scattering (SBS) in single-mode fibers (SMFs). A simple scheme to generate
microwave/millimeter-wave sources is realized by utilizing the optical heterodyne technique between an optical carrier
and its Stokes light. Stable microwave sources with the frequencies of about 10.56 and 21.71 GHz are experimentally
realized using the first- and second-order SBS frequency shifts based on standard SMFs. A microwave frequency
up/down conversion method is presented without premodulation for bi-direction radio-over-fiber systems by using fiber
SBS. The microwave signal of 1.5 GHz is experimentally up-converted to 9.06 and 12.06 GHz, and the microwave
signal of 9 GHz is down-converted to 1.56 GHz, respectively.