Optical downconversion from millimeter-wave to IF-band over 50 km-long optical fiber link using an electroabsorption modulator

Error-free optical downconversion of 40 GHz millimeter (mm)-wave subcarrier multiplexed 156-Mb/s signal to 3 GHz IF-band optical signal at /spl lambda/=1560 nm over 50 km-long nondispersion shifted single-mode-fiber link is experimentally demonstrated by using an electroabsorption modulator but without using any RF mixer. This optical downconversion technique is particularly suitable for the mm-wave radio on-fiber wireless uplink systems because fiber-optic transport of the downconverted IF-band wireless signals can avoid a serious fiber dispersion effect, and low-cost antenna base stations can be realized without any mm-wave active components.