Ian Betty

Performance of MQW InP Mach-Zehnder modulators for advanced modulation formats

The performance of InP modulators is investigated for duobinary and differential phase-shift key transmission. We demonstrate that despite nonlinear phase-voltage characteristics and residual absorption, InP devices give excellent performance comparable to ideal Mach-Zehnder modulators.

A Robust, Low-Crosstalk, InGaAsP/InP Total-Internal-Reflection Switch For Optical Cross-Connect Applications

Cross-connect architectures of semiconductor optical switches will be useful in future communication network applications such as packet and/or wavelength switching.

Low loss, low chirp, low voltage, polarization independent 40 Gb/s bulk electro-absorption modulator module

A 40 GHz electro-absorption modulator module is presented with record unamplified loss (3.6 dB fibre-to-fibre), extremely low PDL (/spl les/0.3 dB over 15 dB extinction) and low absolute chirp (//spl alpha// <0.6 over the full dynamic range) using a highly manufacturable design.

An empirical model for high yield manufacturing of 10Gb/s negative chirp InP Mach-Zehnder modulators

A statistically valid empirical model is used to optimize InP Mach-Zehnder modulators to achieve high yield, wide tunability, record low insertion loss, and dispersion-limited reach superior to that of -0.7/spl alpha/ LiNbO/sub 3/ modulators.

Effect of process-induced stress in InP/InGaAsP weakly confined waveguides

InP/InGaAsP weakly confined wave guides, are of interest for the fabrication of a variety of optoelectronic devices, including optical cross point switches. Previous studies have shown that stress from metallization alters the behavior of these waveguides and the strain-induced changes in refractive index have been investigated by studying the degree of polarization (DOP) from the facets of ridge waveguide (RWG) lasers. However, in devices intended for waveguide routing or switching, e-beam deposited TiPtAu contacts, caused broadening and splitting of the optical near field mode profile after thermal annealing and increased waveguide loss. In this paper, we report the results of a study of process-induced changes on the optical near field mode profile, for different dielectric depositions, metallizations and anneal cycles. It was found that the addition of a layer of the TiPtAu. This not only eliminated the mode splitting, but for sufficiently high values of compressive stress, was found to actually sharpen the mode and enhance the guiding. On the basis of these results stable waveguides, suitable for routing or switching were achieved for a range of device parameters, operating conditions and process parameter variations.

Beyond CFP2-ACO

Summary form only given. Why the CFP2-ACO? Where is it now? Where is it going? Does a CFP4-ACO make any sense? The EO component space evolution over the next 3 years and the roles for ACO and board mounted components.

Techniques for achieving low leakage current in dry etched InGaAs waveguide PIN detectors

InGaAs waveguide PIN detectors require a low leakage current and adequate passivation. Removing dry-etch-induced subsurface damage and surface residues on mesa sidewalls prior to passivation is not only important in reducing these leakage currents, but it is also critical in preventing device degradation. In this article, we investigate the effects of the mesa sidewall clean treatment on the InGaAs waveguide PINs etched using a methane-based (CH4) reactive ion etch (RIE) and a hydrogen bromide-based (HBr) inductively coupled plasma etch (ICP). Post-dry-etching treatments have been developed employing a rapid thermal anneal, followed by a series of Br-, H2SO4-, and HF-based cleaning processes. Transmission electron microscopy analysis shows no apparent sidewall damage, which could cause high leakage currents. Scanning electron microscopy shows sidewall etch by-product removal and ridge CD maintenance after the wet cleaning processes. Very low leakage currents, comparable to those observed in damage-free we...

Short optical pulse generation at 40 GHz with a bulk electro-absorption modulator packaged device

Short optical pulse generation at 40GHz and 1540nm wavelength is achieved using fully packaged bulk quaternary electro-absorption modulator modules. Experimental results obtained with broadband and narrowband optimized packaged modules are presented and compared against empirical model predictions. Pulse duty cycle, extinction ratio and chirp are studied as a function of sinusoidal drive voltage and detuning between operating wavelength and modulator absorption band edge. Design rules and performance trade-offs are discussed. Low-chirp pulses with a FWHM of ~12ps and sub-4ps at a rate of 40GHz are demonstrated. Optical time-domain demultiplexing of a 40GHz to a 10GHz pulse train is also demonstrated with better than 20dB extinction ratio.