High-fidelity lightwave transmission of multiple AM-VSB NTSC signals

Lipson, J.; Upadhyayula, L.C.; Huang, Shih-Jen; Roxlo, C. B.; Flynn, E.J.; Nitzsche, P.; McGrath, Carl J.; Fenderson, G. L.; Schaefer, Matthias

doi:10.1109/22.54915

Cited by 21 publications

(10 citation statements)

References 26 publications

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“…The CNR as well as the nonlinear distortions 2HD, IMD2, and IMD3 are evaluated with the help of Figure that depicts a typical scheme of the modulation response of the laser under two modulation frequencies f m 1 and f m 2 . CNR (in dBc) is calculated as the difference between the power levels (in dB) at the TV channel's visual carrier frequency f m 1 and the noise floor in specified bandwidth centered within the cable television channel . The second‐order intermodulation products occur at f m 1 + f m 2 and f m 2 − f m 1 , whereas the third‐order intermodulation products occur at 2 f m 1 ± f m 2 and 2 f m 2 ± f m 1 .…”

Section: Simulation Modelmentioning

confidence: 99%

“…Figures of merit in the CATV technology include carrier to noise ratio (CNR), composite second order (CSO), and composite triple beat (CTB) distortions. CNR should exceed 50 dBc [1,8,9] in order to avoid the interference of noise with the signal, or the so-called 'snow' that can overwhelm the picture resolution and contrast [10]. CNR is strongly influenced by relative intensity noise (RIN) of the source laser [11][12][13][14][15].…”

Section: Introductionmentioning

confidence: 99%

“…As the lightwave technology has begun to penetrate closer to the subscriber, there has been an intensive interest in the cost‐effective transmission of TV signals . The optical transmission technology was introduced to the cable television (CATV) system .…”

Section: Introductionmentioning

confidence: 99%

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Noise performance and nonlinear distortion of semiconductor laser under two‐tone modulation for use in analog CATV systems

Mahmoud

Ahmed

2015

Int J Numerical Modelling

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We introduce numerical modeling of noise performance and distortion of semiconductor lasers subject to two‐tone modulation according to the National Television Standards Committee NTSC plan for the cable television (CATV) signal transport. The waveform of the laser signal is simulated over wide ranges of the modulation index and placements of the modulation channel. The power and frequency spectra of the relative intensity noise (RIN) are characterized, and the associated second‐order harmonic distortion (2HD), and the second‐order (IMD2) and third‐order intermodulation distortions (IMD3) are calculated. The calculated data are used to predict the measures of the CATV system performance. The dynamic range of linearity of the laser is evaluated in terms of the spurious‐free dynamic range SFDR. We show that under weak modulation, the low‐frequency RIN is constant at −168 dB/Hz regardless the modulation frequency. Within this accepted noise level, IMD2 is 4 dBm higher than 2HD and 10 dBm higher than IMD3. When the modulation index exceeds 25%, the laser emits clipped signals associated with large values of signal distortions. Accepted values of the carrier to noise ratio and distortions correspond to lower modulation index and/or channel frequency. Copyright © 2015 John Wiley & Sons, Ltd.

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Section: Simulation Modelmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Noise performance and nonlinear distortion of semiconductor laser under two‐tone modulation for use in analog CATV systems

Mahmoud

Ahmed

2015

Int J Numerical Modelling

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“…Among these applications, the AM analog CATV system using distributed feedback (DFB) lasers has a great advantage as to cost, compatibility with existing equipment, and signal quality [4]. To achieve adequate signal quality in an AM analog CATV system, high-performance DFB lasers, such as those with high output power, low noise, and low distortion, are required.…”

Section: Introductionmentioning

confidence: 99%

Transmission characteristics of DFB laser modules for analog applications

Yonetani

Ushijima

Takada

et al. 1993

J. Lightwave Technol.

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In this paper, analog transmission characteristics of highly linear 1.3 and 1.55-pm DFB laser modules are described. To obtain high-power and high-performance DFB lasers, the bias dependence of distortion characteristics is discussed. The carrier-to-noise ratio, the composite second-order distortion, and the composite triple beat of the DFB laser module which is developed for analog CATV application are presented. The analog transmission characteristics, such as CNR degradation after fiber transmission, dispersion-induced distortion, and the influence of reflection, have been made clear. The stable high linearity of the DFB laser also has been confirmed by the composite distortion measurement under an accelerated aging test.

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“…These distortions are usually characterized by CSO (Composite Second Order) and CTB (Composite Triple Beat) distortion measurements with unmodulated carriers. CSO is the ratio of the peak power in the largest composite second-order intermodulation tone within each channel to the carrier power related to this channel [5]. This composite tone results from the superposition of several second-order intermodulation tones, each of them arising from the products of the type (f f) with the same resultant frequency (ft, f are carrier frequencies).…”

Section: Linearity Definitions and Requirements For Am-vsb Analog Sysmentioning

confidence: 99%