Yuen-Ching Ku

Enhanced PMD monitoring with frequency-resolved SOP rotation by self-phase modulation

A self-phase modulation (SPM)-assisted polarization-mode-dispersion (PMD) monitoring scheme based on frequency-resolved state-of-polarization rotation is proposed. The use of broadened signal spectrum induced by SPM not only relaxes the filter requirement and reduces the computational complexity, but also improves the estimation accuracy, and extends the monitoring range of the pulsewidth. In this letter, PMD monitoring using this enhanced scheme was studied and experimentally demonstrated with much reduced estimation error, to around 2%, for a 10-Gb/s optical system with 28-ps full-width at half-maximum pulsewidth. In addition, the operation range for the proposed scheme was characterized.

Chromatic dispersion monitoring technique using birefringent fiber loop

A chromatic dispersion monitoring technique using birefringent fiber loop is proposed. An unambiguous measurement range of 1500-ps/nm for 10-Gb/s NRZ signal is demonstrated without transmitter modification. This technique can be used to monitor multiple channels.

A novel technique for pulse-carver and data alignment monitoring in RZ-DPSK systems using off-center optical filtering

A novel technique for monitoring the timing alignment between the pulse carver and the data modulator in return-to-zero differential phase-shift keying systems is proposed and experimentally demonstrated. A simple off-center optical filter is employed to extract optical power for alignment monitoring. Compared with the previous degree of polarization-based monitoring scheme, in which the monitoring power dynamic range (MPDR) is /spl sim/0.2 dB, a larger MPDR of 3.35 dB is achieved within the same timing alignment range of half-bit period, thus achieving a higher monitoring sensitivity. In addition, this simple alignment monitoring scheme features high-speed operation, polarization independence, and easy integration with transmitter for synchronization feedback control.

Robust optical signal-to-noise ratio monitoring scheme using a phase-modulator-embedded fiber loop mirror

We propose and experimentally demonstrate a novel in-band optical signal-to-noise ratio (OSNR) monitoring technique using a phase-modulator-embedded fiber loop mirror. This technique measures the in-band OSNR accurately by observing the output power of a fiber loop mirror filter, where the transmittance is adjusted by an embedded phase modulator driven by a low-frequency periodic signal. The measurement errors are less than 0.5 dB for an OSNR between 0 and 40 dB in a 10 Gbit/s non-return-to-zero system. This technique was also shown experimentally to have high robustness against various system impairments and high feasibility to be deployed in practical implementation.

A novel internetworking scheme for WDM passive optical network based on remodulation technique

We propose and demonstrate a novel internetworking optical network architecture using remodulation technique for WDM-PON. A special connection pattern of AWG in the remote node is used to broadcast the LAN traffic signal to ONUs.

A novel robust OSNR monitoring technique with 40-dB dynamic range using phase modulator embedded fiber loop mirror

A novel in-band OSNR monitoring technique using phase modulator embedded fiber loop mirror (PM-FLM) is proposed and demonstrated. Monitoring error can be kept <0.25 dB for OSNR between 0 to 40 dB in 10-Gb/s non-return-to-zero (NRZ) system.

Wavelength-tunable dispersion-imbalanced loop mirror based on dispersion-flattened high-nonlinearity photonic crystal fiber and its application in suppression of the incoherent interferometric crosstalk

Wavelength-tunable nonlinear suppression of incoherent interferometric crosstalk has been experimentally demonstrated using the dispersion-imbalanced loop mirror based on a 64-m-long dispersion-flattened high-nonlinearity photonic crystal fiber. The signal quality improvement is achieved over a wavelength range of more than 25 nm (1545-1570 nm).

High-Speed Data and Pulse-Carver Alignment in RZ-OOK Systems Using Delay Tap Asynchronous Waveform Sampling

A novel technique for monitoring the alignment status between pulse carver and data modulator in RZOOK systems is proposed and experimentally demonstrated. Both the magnitude and direction of such timing misalignment can be successfully determined.

Nonlinear Suppression of Incoherent Interferometric Crosstalk with Dispersion Imbalanced Loop Mirror using Dispersion-Flattened High-Nonlinearity Photonic Crystal Fiber

Nonlinear suppression of incoherent interferometric crosstalk has been experimentally demonstrated with dispersion imbalanced loop mirror using the dispersion-flattened high-nonlinearity photonic crystal fiber. The signal quality improvement is achieved over a wide wavelength range

A novel technique for modulation alignment monitoring in RZ-DPSK systems using off-center optical filtering

A novel high-speed polarization-independent off-center optical filtering technique for monitoring alignment status between pulse generator and data modulator in RZ-DPSK systems is proposed and demonstrated. A monitoring dynamic range of 3.35 dB is achieved experimentally.