Optical Single-Sideband Modulation With Tunable Optical Carrier to Sideband Ratio in Radio Over Fiber Systems

Novel Vestigial Sideband Modulation Scheme to Enhance the SNR in Radio Over Fiber Systems

“…Some slightly complex methods have been reported for achieving the SNR optimization goal [6], [7], [11]. These methods include DMZM with tunable optical filter, using polarization modulators, optical injection locked laser based technique, etc.…”

“…To maximize the SNR of the OSSB based RoF link, the optimization of optical carrier to sideband ratio (OCSR) at 0 dB is important [6], [7]. Generally, to generate the OSSB scheme either an electro optic modulator along with an optical filter, or a dual electrode modulator (DMZM) is used [8], [9].…”

OSSB modulation of tunable optical carrier-to-sideband ratio with FBG-based acousto-optic tunable filter

“…Radio over Fiber (RoF), the integration of wireless and optical systems, has been considered a promising technology in wide applications due to its unique advantages of low cost, low loss, high capacity and high immunity to electromagnetic interferences [1][2][3][4][5]. High quality millimeter-wave signal generation technology is one of the key technologies to realize low cost and high transmission performance in the RoF systems.…”

“…Among all of them, the method of employing an external modulator to realize OSSB modulation has attracted significant interests. OSSB modulation technique shows some advantages, including that the RF signals transmission does not experience dispersion-induced power fading and the channel bandwidth is only half of the ordinary intensity modulation [3,[7][8][9][10]. However, in the conventional OSSB modulation scheme, as the RF driving signals are always weakly modulated onto the optical carrier due to the low modulation efficiency, the power of the optically modulated RF sidebands is much lower than that of the optical carrier, which means that the optical carrier to sideband ratio (OCSR) is much higher than 0 dB.…”

Variable carrier reduction in radio-over-fiber systems for increased modulation efficiency using a Si_3N_4 tunable extinction ratio ring resonator

“…This technique is useful in systems where the modulation efficiency is limited and the overall optical power cannot be increased due to the danger of saturating the photodetector. Carrier reduction has so far been implemented via Brillouin scattering [4,5], use of dual-parallel Mach-Zehnder modulators [6] and external optical filtering using silica delay lines [7], Fabry-Perot structures [8], fiber Bragg gratings [9,10] and arrayed waveguide gratings (AWG) [11].…”