A description is given of a GaAs-AlGaAs, loaded-line traveling-wave modulator which has achieved bandwidths up to 36 GHz to date with low ( >

High-speed III-V semiconductor intensity modulators

Because the electroabsorption effect in semiconductor multiple quantum well material is approximately 50 times larger than in bulk semiconductors, significant interest has been generated in the use of MQW's in optical modulators Small high-speed devices have been made which show promise for external modulators in optical transmission systems, as well as for encoding and processing components in optical interconnect and signal processing systems The fact that these modulators are made from III-V semiconductors had led to interest in integration of these components with other active optoelectronic components Although most devices have operated with light of a wavelength of 085 mu m, recently much progress has been made in applying this technology to devices operating near 155 mu m The author reviews the work of the last few years in this field and indicates some future directions >

Multiple quantum well (MQW) waveguide modulators

A review is presented of recent progress in low-loss III-V semiconductor integrated optics for the 1-1.6 mu m wavelength range, including propagation, bending, coupling, and modulator losses. Tradeoffs between loss and other performance issues are discussed in detail. The authors show that significant advances have resulted in a research shift from work on the general issues of improved material transparency and straight guide propagation loss to more application-specific areas. In particular, size-loss tradeoffs in bend and modulator structures remain key issues for widespread use of III-V integrated optics. >

Low-loss III-V semiconductor optical waveguides

Current–voltage and capacitance–voltage characteristics of polypyrrole/p-InP structure

A new insulation film, PO x N y H z , has been fabricated on n -InP substrate surface using vapor transport technique for use as an interfacial layer on n -InP Schottky contact devices. This interfacial layer is obtained by reaction of the deposited film with the substrate surface. It is stable and moisture insensitive. The capacitance voltage and current voltage characteristics are determined at various temperatures. Temperature dependence of ideality factor and apparent barrier height is observed. The Richardson plot gave a good straight line. At room temperature, the ideality factor is about 1.09; the apparent and true barrier heights evaluated from extrapolated forward saturation current and from Richardson plot ln ( I 0 T 2 ) vs 10 3 T respectively, are found to be equal to 0.80 and 0.39 eV; the reverse current density is found to be sufficiently low (6.4·10 −8 A / cm 2 at IV). The characteristics of the prepared Schottky device are analyzed.

High barrier height Au/n-type InP Schottky contacts with a POxNyHz interfacial layer

We report a 13‐μm GaAs traveling‐wave electro‐optic waveguide modulator with a 3‐dB optical bandwidth in excess of 20 GHz The bandwidth was determined by directly detecting the modulated optical signal with a high‐speed InP/GaInAs photodiode The modulator has a coplanar strip electrode configuration with a double heterojunction Al0032Ga0968As/GaAs/Al0032Ga0968As optical guide grown by low‐pressure organometallic vapor phase epitaxy

S. Y. Wang

Papers

GaAs traveling‐wave polarization electro‐optic waveguide modulator with bandwidth in excess of 20 GHz at 1.3 μm