We present a planar lightwave circuit curved 2/spl times/2 coupler. Its splitting ratio has a low sensitivity to wavelength, polarization, and fabrication yet is low-loss and compact. We present simple formulae for its design. We demonstrate a 50/50 version in silica-on-silicon waveguides. We discuss the tradeoff between amplitude accuracy and phase accuracy in such densensitized couplers.

A wide-tuning-range optical delay line is demonstrated in high (2%) index contrast waveguides. This device integrates four-stage ring resonator all-pass filters (APFs) with cascaded fixed spiral-type delay waveguides; each fixed delay path varies in length by a factor of two from the previous stage. A 2 x 2 switch separates each fixed delay and the tunable parts of the delay line. The APF allows for continuous delay tuning. This device enables coherent switching and continuous tuning ranges up to 2.56 ns.

A wide-tuning-range optical delay line is demonstrated in high (2%) index contrast waveguides. This device integrates 4-stage ring resonator all-pass filters (APFs) with cascaded fixed spiral-type delay waveguides; each fixed delay path varies in length by a factor of 2 from the previous stage. A 2x2 switch separates each fixed delay and the tunable parts of the delay line. The APFs allow for continuous delay tuning. This device enables coherent switching and continuous tuning ranges greater than 2.56ns.

We demonstrate a monolithic high-performance reconfigurable optical add-drop multiplexer (ROADM) with integrated 24/spl times/8 wavelength selecting optical cross-connect. Eight of the 24/spl times/100 GHz WDM channels may be dropped to any of 8 wavelength-independent drop ports.

We describe a wide range of reconfigurable optical add-drop multiplexer architecture designs that may be implemented in standard silica-on-silicon planar lightwave circuits. This proven, reliable technology offers high performance and cost-effective solutions for reducing complex service provisioning in reconfigurable optical networks. Recent advances enable very flexible wavelength routing devices for mesh- and ring-based networks to be implemented on a common subsystem integration platform. We show excellent system performance at 10 Gb/s.

Feature Issue on Optical Performance Monitoring (OPM). An integrated, high-resolution spectral polarimeter is demonstrated in 4%-index-contrast Ge-doped silica waveguides. A ring resonator achieves a wavelength selectivity of less than 2 GHz FWHM, and tunability is realized via thermo-optic phase shifters with scanning speeds on the millisecond time scale. Real-time, in-service polarization-mode dispersion monitoring is thus possible for studying dynamic channel behavior and for feedback to adaptive compensators. Measurements of the differential group delay, output state of polarization, and principal states of polarization of 10- and 40-Gbit/s modulated signals are presented. Measurements of time-varying PMD and higher-order PMD are also presented to demonstrate the device's capability.

Wide-tunable-range optical delay lines are demonstrated in high index contrast waveguides. This device integrates tunable allpass filters, for continuous delay tuning, with cascaded fixed delay waveguides enabling coherent switching and tuning ranges up to 2.56ns.

Highly versatile building blocks for polarization-mode dispersion (PMD) emulation and compensation are demonstrated using tunable all-pass filters fabricated in 4%-index-contrast planar waveguides. While the all-pass filters can approximate any phase response, the complexity in setting the individual filter parameters is minimized by restricting the all-pass filter responses to realize a range of differential delays, dispersion, and dispersion slope. A single section can approximate first-order or a higher-order PMD term or emulate chromatic or higher-order dispersion. A differential group delay (DGD) tuning range over 100 ps is demonstrated for 10 Gb/s and 25 ps for 40 Gb/s data. Second-order PMD with a tuning range of 255 ps/sup 2/ and third-order PMD with a range of 2430 ps/sup 3/ are also demonstrated. The larger index contrast required for the ring-resonator-based all-pass filters is advantageous in reducing the thermooptic response time to achieve polarization rotation speeds on the order of 0.1 /spl mu/s/degree. The device is interferometrically stable and compact in size. It can be fully integrated, scaled to many sections, and can implement a variety of PMD synthesis and statistical-emulation approaches.

We report experiments on a continuously tunable true time delay and demonstrate high resolution tuning for the first time using a multi-stage all-pass filter device implemented with Ge-doped silica planar lightwave circuits.

Fully integrated variable optical attenuator multiplexers (VMUX) with substantial performance improvements, notably very low loss and PDL, are reported. Reduced power consumption by deep etching is also demonstrated.

Get PDF Email Share Share with Facebook Tweet This Post on reddit Share with LinkedIn Add to CiteULike Add to Mendeley Add to BibSonomy Get Citation Copy Citation Text M. Earnshaw, M. Cappuzzo, E. Chen, L. Gomez, A. Griffin, E. Laskowski, and A. Wong-Foy, "Reconfigurable Optical Add-Drop Multiplexer (ROADM) with full add and drop path crossconnect," in Optical Amplifiers and Their Applications/Integrated Photonics Research, Technical Digest (CD) (Optica Publishing Group, 2004), paper IThA2. Export Citation BibTex Endnote (RIS) HTML Plain Text Citation alert Save article

The retiming and reshaping properties of a 160 Gbit/s all-optical wavelength converter based on a semiconductor optical amplifier gating delay interferometer configuration is investigated. 160 Gbit/s operation is performed with as little as -3.5 dBm input signal.

We describe the wide range of wavelength switching functions that may be implemented in standard silica-on-silicon waveguide technology. This proven, reliable technology offers high performance and cost-effective solutions for reducing complex service provisioning in reconfigurable optical networks.

An endless, reset-free polarization controller implemented with planar lightwave circuits using phase shifters for tuning is proposed and demonstrated. By avoiding the need for tunable polarization mode converters, simple fabrication processes and a large range of material systems can be used, since neither the electrooptic effect nor a rotatable birefringence axis are necessary for device operation. The proof of concept is demonstrated by implementing the equivalent of a rotating waveplate using Ge-doped silica-on-silicon waveguides; and thermooptic phase shifters. The polarization controller is shown to have excellent tolerance to fabrication variations. Fast thermooptic control (on the order of 10 kHz) is achieved using high-index-contrast (4%) waveguides.

Polarization beam splitters are demonstrated in 4% index-contrast Ge-doped silica waveguides with extinction ratios exceeding 24dB over a wavelength range of 80nm. Integration with ring resonators and a double-pass, reflective architecture are also presented.

The first demonstration of large-scale integration of AWG filters and thermo-optic switches and attenuators in 2% delta silica-on-silicon waveguides is reported. A compact high performance wavelength selective switch is demonstrated.

Get PDF Email Share Share with Facebook Tweet This Post on reddit Share with LinkedIn Add to CiteULike Add to Mendeley Add to BibSonomy Get Citation Copy Citation Text C. K. Madsen, E. J. Laskowski, M. Cappuzzo, E. Chen, L. Gomez, A. Griffin, and A. Wong-Foy, "PMD and PDL Emulation using Integrated Variable Delay Lines," in Integrated Photonics Research, A. Sawchuk, ed., Vol. 91 of OSA Trends in Optics and Photonics (Optica Publishing Group, 2003), paper IMC5. Export Citation BibTex Endnote (RIS) HTML Plain Text Citation alert Save article

We present a fully integrated 20-channel wavelength selective switch with reduced size and power consumption. We show for the first time large-scale integration of AWG filters and thermo-optic switches and attenuators in 2% delta silica-on-silicon waveguides. The on-chip loss is less than 7 dB with 3 OdB isolation performance.

PMD and chromatic dispersion emulator and compensator architectures using allpass filters are presented. The tuning range and bandwidth for 10 and 40 Gb/s using planar waveguide ring resonators with 75 GHz FSR are discussed.

Tunable dispersion compensators for 10 and 40 Gb/s signals using planar waveguide ring-resonator allpass filters are reviewed. Recent work using tunable ring-resonators as building blocks for PMD emulation, compensation and monitoring are also discussed.