25-GHz channel spacing dwdm multiplexing using an arrayed waveguide grating for 60-GHz band radio-on-fiber systems

Radio-over-fiber systems

“…To improve the link performance, the optical power of the signals can be increased by using a high power optical source or an optical amplifier; however, this may lead to increased intermodulation distortions at the receiver or even damage of the receiver due to a too large optical power incident on the optical detector [21]. A few techniques have been proposed to improve the modulation efficiency of these signals including Brillouin scattering [21,22], external optical filtering [23,24], and optical attenuation [25]. Fig.…”

Optical impairments mitigation in millimeter-wave fiber-wireless systems

“…To improve the link performance, the optical power of the signals can be increased by using a high power optical source or an optical amplifier; however, this may lead to increased intermodulation distortions at the receiver or even damage of the receiver due to too large an optical power incident on the optical detector [14]. A few techniques have been proposed to improve the modulation efficiency of these signals including Brillouin scattering [14,15], external optical filtering [16,17], and optical attenuation [18]. Fig.…”

“…However this approach may lead to increased IMDs at the receiver or even damage the receiver due to too large an optical power incident on the optical detector [14]. Alternatively, a few techniques have also been proposed to improve the low mm-wave modulation efficiency, including Brillouin scattering [14,15] and external optical filtering [16][17][18]. Apart from low modulation efficiency, the optical distribution of mmwave radio signals is also susceptible to fiber chromatic dispersion that severely limits the transmission distance [19,20].…”

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].…”