Benjamin John Eggleton

Measurement of residual chromatic dispersion of a 40-Gb/s RZ signal via spectral broadening

In this letter, we examine the spectrum of a 40-Gb/s return-to-zero (RZ) data stream, which has been broadened by self-phase modulation in a nonlinear fiber. Spectra were recorded as the residual chromatic dispersion at the input of the nonlinear fiber was varied using a tunable dispersion element. We show that spectral broadening can provide a useful measure of the residual chromatic dispersion of the data stream.

Compression of optical pulses spectrally broadened by self-phase modulation with a fiber bragg grating in transmission.

We demonstrate experimentally the compression of optical pulses, spectrally broadened by self-phase modulation occurring in the rod of a mode-locked Q-switched YLF laser, with an unchirped, apodized fiber Bragg grating in transmission. The compression is due to the strong dispersion of the Bragg grating at frequencies close to the edge of the photonic bandgap, in the passband, where the transmission is high. With the systems investigated, an 80-ps pulse, which is spectrally broadened, owing to self-phase modulation, with a peak nonlinear phase shift of D? = 7, is compressed to approximately 15 ps, in good agreement with theory and numerical simulations. The results demonstrate that photonic bandgap structures are promising devices for efficient pulse compression.

Holographic methods for phase mask and fiber grating fabrication and characterization

The fiber grating fabrication based on use of the phase masks is the most stable and accurate manufacturing technology. This paper presents a brief overview of holographic methods of phase masks and fiber Bragg gratings (FBGs) writing and characterization with emphasis on the chirped gratings. We discuss the range of FBG parameters enabled by current technological methods, as well as the relation between the accuracy of FBG parameters and the performance of FBG-based dispersion compensators. While holographic phase mask and FBG writing principles have much in common, the phase mask and FBG production is a unified technology where the quality of the FBG is determined by numerous factors in the process of fabrication. As one of the significant factors, we study the effect of mirror non-flatness on the group delay ripple of chirped FBG. The quality of phase masks and FBGs is often important to characterize directly. In this paper we consider holographic side-diffraction methods of their characterization, which are very accurate and provide the information that is not simple to obtain from spectroscopic measurements.

Reduction of chirped fiber grating group delay ripple penalty through UV post processing

We demonstrate adiabatic UV correction of smoothed group delay ripple from /spl plusmn/10 ps to /spl plusmn/2 ps yielding reduction of OSNR penalty (40Gbit/s CSRZ) from /spl sim/ 4 dB to 0.5 dB over the tunable dispersion range of 270 to 750 ps/nm.

Side-diffraction technique for highly accurate characterization of fiber Bragg grating index modulation

We demonstrate a technique for simultaneous measurement of fiber grating refractive index modulation (accuracy/spl sim/2/spl times/10/sup -6/) and grating period variation (accuracy/spl sim/5 pm) and apply our technique to direct calculation of chirped fiber grating group delay ripple.

Multifunctional, tunable microfluidic optical fiber devices

By introducing microfluidic plugs into interior fiber microchannels, we have developed a new category of active, tunable optical fiber. The positions and optical properties of the fluidic plugs can be directly controlled by utilizing actuators and pumps located on the fiber surface, thereby allowing the propagation characteristics of certain optical fiber modes to be usefully adjusted. These hybrid microfluidic/silica waveguides preserve the advantages of conventional, passive optical fiber, while at the same time providing versatile tuning capabilities. Examples of variable narrow and broadband all-fiber filters are described here. These fluidic fiber devices have the potential to be important technologies for next generation optical networks.