E. Laskowski

Integrated resonance-enhanced variable optical delay lines

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/spl times/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.

DISTRIBUTED FEEDBACK RIDGE WAVEGUIDE LASERS FABRICATED BY NANOSCALE PRINTING AND MOLDING ON NONPLANAR SUBSTRATES

This letter describes the use of printing and molding techniques to fabricate plastic photopumped laser that use distributed feedback resonators on ridge waveguides. The results indicate (i) potential optoelectronic applications of a set of emerging low cost lithographic techniques that can pattern a range of materials with submicron resolution on nonplanar substrates, (ii) a new type of plastic laser based on molded organic gain materials, and (iii) that thresholds of plastic distributed feedback ridge waveguide lasers are similar to their planar counterparts.

Dynamic wavelength equalizer in silica using the single-filtered-arm interferometer

A dynamic wavelength equalizer that can control attenuation at 22 points across 35 nm of spectrum in a smooth manner is presented. It achieves low loss (4.7 dB), because it consists of a Mach-Zehnder interferometer with a wavelength-dependent element in only one arm. Additional development is needed to reduce the polarization sensitivity.

Large N x N waveguide grating routers

We show how the grating diffraction properties of a N/spl times/N waveguide grating router (WGR) can limit the size of N when the device operates with a unique set of N wavelengths as a strict-sense nonblocking N/spl times/N cross connect. We motivate why for large N, the N optical channels should be chosen equally spaced in wavelength and not in frequency. Two different approaches to increase N are presented. We report on results obtained in a 40/spl times/40 and a 80/spl times/80 WGR.

Operation of a fully integrated GaAs-Al/sub x/Ga/sub 1-x/As FET-SEED: a basic optically addressed integrated circuit

The authors experimentally demonstrate the operation of a fully integrated optoelectronic circuit with optical input and output consisting of a p-i-n photodetector and load resistor, a depletion-mode GaAs-Al/sub x/Ga/sub 1-x/As heterostructure field-effect transistor (HFET) and self-biased HFET load, together with an output GaAs-Al/sub x/Ga/sub 1-x/As multiple quantum-well optical modulator. All elements have been monolithically integrated within a 50- mu m*50- mu m area. A low optical power input causes a modulation of a higher-power output, demonstrating optical signal amplification.<<ETX>>

Resonators and materials for organic lasers based on energy transfer

Optically pumped lasers have been fabricated with organic/polymeric materials capable of charge transport. The active materials employed are doped films with small molecule hosts and dye, oligomer, and conjugated polymer emitters. In these materials, the excited states created in the host are transferred nonradiatively to the guest molecules which are the emitters. This energy transfer results in very low absorption losses at the emission wavelength and relatively low-threshold powers for the onset of stimulated emission. Such gain media have been successfully included in many types of resonators including whispering-gallery mode, photonic bandgap, and distributed Bragg reflector (DBR) based resonators. A number of novel patterning and fabrication procedures have been developed for organic-based lasers.

40-wavelength add drop filter

We present in 40-wavelength, 100-GHz channel spacing, programmable, planar add-drop filter that has flattened passbands without excess loss. For TE polarized light, the insertion loss is 9-11 dB for the through channels, and the dropping extinction ratio is /spl ges/33 dB.

All-optical wavelength conversion and broadcasting to eight separate channels by a single semiconductor optical amplifier delay interferometer

We have demonstrated an all-optical broadcast experiment in which a 10 Gbit/s RZ data signal is simultaneously converted into up to 8 different wavelengths. A single SOA with delay interferometer was used. Bit error rate measurements showed a power penalty of less than 1.5 dB for configurations with up to 8 wavelengths.

An automatic 40-wavelength channelized equalizer

We demonstrate a wavelength equalizer in planar silica waveguides that can automatically control individual channel powers in a 40-channel 100-GHz-channel-spacing wavelength-division multiplexed system, yet gives no distortion to channels that already have the same power as their neighbors. It has <6.8 dB insertion loss over 32-nm, 9-13-dB attenuation range, and <0.18 dB polarization/time-dependent loss.

Eight-wavelength add-drop filter with true reconfigurability

The authors demonstrate an integrated add-drop filter with true reconfigurability. It can drop any combination of eight wavelengths to any of eight drop ports, with less than 7 dB loss. Its features are suitable for mass production: use of standard silica waveguide technology, double-rejection switching and filtering for all paths, compactness, and power-efficient thermooptic switching.