Fiber Optic Intermodulation Distortion

Fiber to the Home Using a PON Infrastructure

“…As in the SCMA scheme, the required modulation bandwidth is typically quite large due to the double-sided nature of the RF-modulated signals and the required RF-frequency locations to avoid any nonlinear distortions [18]. In addition, extra care is required to avoid any clipping noise induced by the threshold characteristics of the laser transmitter [19].…”

Harmonic and Intermodulation Performance of Quantum-Well Mach-Zehnder Electro-Optic Modulators with Electrical Biasing

“…Combining equations (16)(17)(18)(19)(20)(21), the relative second-harmonic, second-order intermodulation, third-harmonic, third-order intermodulation type 2ω 1 -ω 2 and third-order intermodulation type ω 1 ± ω 2 ± ω 3 distortion in the output of the QCSE Mach-Zehnder EOM can be expressed as…”

“…However, in most practical cases, the principle source of intermodulation distortion is the third-order intermodulation products expressed by equations (20) and (21). This intermodulation distortion can be reduced by carefully controlling the tone frequencies ω r to be equally spaced [17]. The number of intermodulation products of the type 2ω q -ω r falling of the rth tone in a sequence of K equally spaced tones is given by [18] …”

Analysis of laser overmodulation techniques in subcarrier multiplexed optical fibre systems

“…Based on the approach of Daly [9], the laser can be modelled as a nonlinearity without memory. The light output is expressed as a function of the modulating current by a third order polynomial of the form…”

“…Static nonlinearity can be modelled as a memoryless nonlinearity based on the light-current (L/I) characteristic of a laser [ 9 ] . This approach, which can be traced back to Bennett [ l o ] in 1940 for determining the intermodulation distortion in multichannel amplifiers, is readily applicable to the analysis of multicarrier systems.…”