Parametric Tunable Dispersion Compensator Research Articles

Autonomous Parametric Tunable Dispersion Compensation for Dynamic Optical Switching

We demonstrate dynamic parametric optical dispersion compensation in dynamic optical path networks (DOPNs). A fully automatic parametric tunable dispersion compensator (P-TDC) based on four-wave mixing process is developed with a fast tunable distributed amplification chirped sampled grating distributed reflector laser, a field-programmable gate array (FPGA) pump controller, and a fast dispersion monitor based on spectral shearing interferometer. The dispersion monitor detects a change in the dispersion of a path, and the monitoring signal is fed forward to the FPGA controller. The fast tunable laser sets its wavelength accordingly for the dispersion compensation through parametric process. A response time of <17 ms is demonstrated in a testbed of DOPN. The autonomous P-TDC has a potential response of submillisecond.

Sub-millisecond timing-jitter-free tuning of parametric dispersion compensator

We demonstrate sub-millisecond tuning of a prototype parametric tunable dispersion compensator (P-TDC) based on cascaded polarization-diverse four-wave mixing (FWM) process with a fast tunable and highly wavelength-stable pump light source. The pump light source is developed using a tunable distributed amplification chirped sampled grating distributed reflector laser that is fully wavelength tunable by on-chip heaters with a 3-dB frequency response of 45 kHz, resulting in fast dispersion tuning of less than 50 μs without additional timing jitter. The P-TDC is developed as the first prototype to satisfy essential requirements for practical network uses: stable input-polarization diversity, input-wavelength preservation, and seamless dispersion tunability for entire C-band input wavelengths are simultaneously achieved.

Experimental study on parametric tunable dispersion compensation for WDM channels with mixed OOK and QPSK formats

Presented is a parametric tunable dispersion compensation (PTDC) for 43 Gbit/s WDM channels with mixed modulation formats of OOK and QPSK. The residual dispersion for the OOK channels is successfully compensated for, while the QPSK channels with digital coherent detection maintain a good signal quality regardless of various settings of PTDC that involve nonlinear processes of wavelength conversion based on four-wave mixing. Specific design issues on PTDC are discussed, considering the characteristics of the modulation formats of the received channels.

In-Line Polarization-Insensitive Parametric Tunable Dispersion Compensator for WDM Signals

We develop frequency-preserving parametric tunable dispersion compensator (P-TDC) with polarization diversity for simultaneous dispersion compensation of wavelength division multiplexing channels. The in-line polarization-insensitive P-TDC is composed of cascaded parametric tunable frequency converters based on degenerate four-wave mixing process in polarization-maintaining highly nonlinear fibers with a low dispersion slope. Dispersion-managed error-free transmission of four channels of 43 Gb/s nonreturn-to-zero ON-OFF keying signal is successfully demonstrated over 126 km dispersion-shifted fiber with the in-line polarization-insensitive P-TDC.

Parametric Tunable Dispersion Compensation With Spectrally Noninverting Wavelength Conversion Using Quasi-Phase-Matched Adhered Ridge Waveguide

We develop a highly efficient quasi-phase-matched adhered ridge waveguide (QPM-ARW) in LiNbO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> as a nonlinear material, and demonstrate tunable wavelength conversion without spectral inversion (SI) and parametric tunable dispersion compensation for a single-mode fiber (SMF) link. The QPM-ARW module with a second harmonic generation efficiency of 700 %/W achieves tunable wavelength conversion with a wavelength-tuning range of at least 25 nm through cascaded sum- and difference-frequency generation (SFG-DFG) process in which the signal and pumps are located symmetrically around the phase matching wavelength. The power penalty of the wavelength conversion is less than 0.6 dB for 43-Gb/s nonreturn-to-zero on-off-keying (NRZ-OOK) signals. We then apply the tunable wavelength conversion without SI to the parametric tunable dispersion compensation scheme, and achieve successful optical tunable dispersion compensation in 43-Gb/s NRZ-OOK transmissions over 53.2-km SMF.

Parametric tunable dispersion compensation for the transmission of sub-picosecond pulses

Parametric tunable dispersion compensator (P-TDC), which allows format-independent operation owing to seamlessly wide bandwidth, is expected to be one of the key building blocks of the future ultra-high speed optical network. In this paper, a design of ultra-wide band P-TDC is presented showing that bandwidth over 2.5 THz can be achieved by compensating the chromatic dispersion up to the 4th order without employing additional method. In order to demonstrate the potential application of P-TDC in the Tbit/s optical time division multiplexing transmissions, 400 fs optical pulses were successfully transmitted through a dispersion managed 6-km DSF fiber span.

Field Demonstration of Parametric Tunable Dispersion Compensator Employing Polarization Diversity Scheme

We report long-term polarization-insensitive operation of a parametric tunable dispersion compensator (P-TDC) in 43-Gb/s NRZ-OOK transmission over 105-km field-installed fiber. The P-TDC employs polarization diversity loop using polarization-maintaining highly nonlinear fiber with a low dispersion slope. Stable dispersion-managed transmission for more than 8 hours is achieved under the polarization-fluctuating conditions in the field-installed fiber.

Polarisation-insensitive parametric tunable dispersion compensator

Polarisation-insensitive operations of a parametric tunable dispersion compensator based on a polarisation diversity scheme using a polarisation-maintaining highly nonlinear fibre are demonstrated. The polarisation-dependent power penalty is less than 0.5 dB for 43 Gbit/s non-return-to-zero on-off-keying signals with polarisation scrambling.

Microsecond switching of parametric tunable dispersion compensator

A record-fast, 2 μs switching operation of an optical tunable dispersion compensator is demonstrated with a parametric tunable dispersion compensation scheme. We alternately switch two optical paths having different net dispersions with a microsecond guard interval of the compensator response and achieve successful transmissions of 43 Gbit/s non-return-to-zero on-off-keying optical signals. The error-free guard time for the switching of the two optical paths is 125 μs, limited mostly by the clock synchronization of the bit-error detector. The power penalty due to the switching of the compensator is less than 0.5 dB.

High-speed optical transmissions over a second- and third-order dispersion-managed DSF span with parametric tunable dispersion compensator

A wideband and fast tunable chromatic dispersion compensator is one of the key components for the future high-speed optical transmissions. We have so far proposed and demonstrated a new tunable dispersion compensation scheme called parametric tunable dispersion compensator (P-TDC), which is based on the combination of parametric frequency conversion and frequency dependent dispersive media. The P-TDC has many attractive features such as a seamlessly wideband operation, wide tunable range and fast dispersion tuning. In fact, with appropriate configurations of dispersive media, the P-TDC can compensate the dispersion slope of transmission fibers even though the second-order dispersion is small. In this paper, we use such a P-TDC scheme and successfully achieve high-speed optical transmissions over a second- and third-order dispersion managed dispersion shifted fiber (DSF) span. The transmission experiments show low-penalty 172 Gbit/s return-to-zero on-off-keying transmissions over 126-km DSF.