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Lightwave Catalog: Optical-Electrical/Polarization/Complex Modulation Analysis 2013 Vol 2

Lightwave Catalog: Optical-Electrical/Polarization/Complex Modulation Analysis 2013 Vol 2
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LIGHTWAVE CATALOG Optical-Electrical/Polarization/Complex Modulation Analysis

Agilent Technologies Lightwave Catalog 2013 Since more than 30 years, Agilent offers high-performance solutions to support you in building the high-speed communication network. Your experience and feedback helped us to continuously improve the product performance and quality, while significantly reducing the cost, especially when it comes to manufacturing optical components. Your needs and my confidence into our quality let me now offer our products with a 3-year warranty that's standard on all instruments, worldwide. This combination of reliability and coverage brings you three key...

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Lightwave Catalog: Optical-Electrical/Polarization/Complex Modulation Analysis 2013 Vol 2 - 3

Understand the real nature of complex modulated signals The new Agilent N4392A optical modulation analyzer (OMA) lets you see the true nature of complex modulated signals. Powered by the Agilent 89600 vector signal analysis software, you get deeper analysis and greater flexibility. At a fraction of the cost, size and weight of a typical OMA, you can N4392A optical modulation anal Compact, portable and affordable 32 Gbaud symbol rate 63 GSa/s sample rate Agilent Technologies

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Lightwave Catalog: Optical-Electrical/Polarization/Complex Modulation Analysis 2013 Vol 2 - 5

Optical Modulation Analysis Tools The l-Q diagram (also called a polar or vector diagram) displays de- modulated data, traced as the in-phase signal (I) on the x-axis versus the quadrature-phase signal (Q) on the y-axis. This tool gives deeper insight into the transition behavior of the signal, showing overshoot and an indication of whether the signal is bandwidth limited when a transition is not close to a straight line. Optical constellation diagram In a constellation diagram information is shown in a two-dimensional polar diagram, displaying amplitude and phase of the signal. The...

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Lightwave Catalog: Optical-Electrical/Polarization/Complex Modulation Analysis 2013 Vol 2 - 6

Applications Optical Modulation Analysis Tools www.agilent.com/find/oma Error vector magnitude Error vector limit test The error vector time trace shows computed error vector between measured I-Q points and the reference I-Q points. The data can be displayed as error vector magnitude, error vector phase, the I component only or the Q component only. The error vector concept is a very powerful way to qualify the overall performance of an complex modulated signal. Testing against a limit with pass/fail indication covers all typical error sources that could occur during transmitter...

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Lightwave Catalog: Optical-Electrical/Polarization/Complex Modulation Analysis 2013 Vol 2 - 7

Applications Coherent Transmitter and Modulator Test www.agilent.com/find/n4392a Transmitter laser Transmitter signal integrity characterization • Transmitter signal performance verification • Verify optimal alignment biasing circuits and skews • Transmitter vendor qualification • Final pass fail test in manufacturing • Evaluation of transmitter components for best signal fidelity Beam splitter X-plane modulator Y-plane modulator Polarization combiner Signal input Transmitter laser Beam splitter X-plane modulator Y-plane modulator Local oscillator input Polarization combiner Signal input...

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Lightwave Catalog: Optical-Electrical/Polarization/Complex Modulation Analysis 2013 Vol 2 - 8

Coherent Transmiiter Test in Manufacturing Optical constellation diagram In a constellation diagram, signal information is shown only at the middle of a symbol time. This represents exactly the time stamp a real receiver will take to decide on the transmitted data. These points are commonly referred to as detec- tion decision-points-, and are interpreted as the digital symbols. Constellation diagrams help identify effects like amplitude imbalance, quadrature error, or phase noise just to mention some of them. For calculating the BER based on statistical data a Gaussian noise distortion is...

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Lightwave Catalog: Optical-Electrical/Polarization/Complex Modulation Analysis 2013 Vol 2 - 9

Advanced research on OFDM OFDM high resolution spectrum An ODFM signal is a set of carriers that are orthogonal and very closely spaced in frequency domain, which lets the spectrum appear rectangular in a perfect signal. In addition a ODFM signal often carries pilot and synchronization information at different power levels. With high resolution spectral display, a quantitative analysis of the OFDM signal can be done in parallel with the other analysis tools.

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Lightwave Catalog: Optical-Electrical/Polarization/Complex Modulation Analysis 2013 Vol 2 - 10

Applications Research on Modulation Formats www.agilent.com/find/n4392a Customer configurable APSK demodulator This new generic decoder allows the user to configure a custom decoding scheme in accordance with the applied IQ signal. Up to 8 amplitude levels can be combined freely with up to 256 phase levels. This provides nearly unlimited freedom in research to define and evaluate the transmission behavior of a proprietary modulation format. The setup is easy and straightforward. Some examples are shown below. Optical duobinary decoder In 40 G transmission systems, an optical duobinary...

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Lightwave Catalog: Optical-Electrical/Polarization/Complex Modulation Analysis 2013 Vol 2 - 11

Impairments in Complex Modulation Transmission To describe the quality of a complex modulated signal, there are a variety of parameters in place. Quad Err = 36 824 rndeg Gain Imb = D 024 dB IQ offset (also called l/Q origin offset) indicates the magnitude of the carrier feed through signal. When there is no carrier feed through, IQ offset is zero (-infinity dB). Magnitude error Magnitude error is the difference in amplitude between the measured signal and the l/Q reference signal. Phase error Phase error is the phase difference between the l/Q reference signal and the l/Q measured signal,...

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Lightwave Catalog: Optical-Electrical/Polarization/Complex Modulation Analysis 2013 Vol 2 - 12

Impairments in Complex Modulation Transmission SNR (MER) - signal to noise ratio (modulation error ratio) SNR (MER) - Signal to Noise Ratio (Modulation Error Ratio) is the signal-to-noise ratio, where signal is the average symbol power of the transmitted waveform. The noise power includes any term that causes the symbol to deviate from its ideal state Note: SNR and 0SNR are only equal in Gaussian noise limited systems, when proper normalization is used (0SNR is typically measured with Error vector and error vector magnitude as a global measure EVM %rms is a normalized measure of all error...

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Lightwave Catalog: Optical-Electrical/Polarization/Complex Modulation Analysis 2013 Vol 2 - 13

Applications Lightwave Component Analysis www.agilent.com/find/lca In digital photonic transmission systems, the performance is ultimately determined by Bit Error Ratio Test (BERT). As this parameter describes the performance of the whole system, it is necessary to design and qualify subcomponents like modulators and PIN detectors, which are analog by nature, with different parameters that reflect their individual performance. O/E characterization The measurement of an electro-optical receiver device consists of the ratio of output electrical modulation current to input optical modulation...

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