Integrated InP polarization converters based on half-ridge structure are studied numerically. We demonstrate that the fabrication tolerance of the half-ridge structure can be extended significantly by introducing a slope at the ridge side and optimizing the thickness of the residual InGaAsP layer. High polarization conversion over 90% is achieved with the broad range of the waveguide width from 705 to 915~nm, corresponding to a factor-of-two or larger improvement in the fabrication tolerance compared with that of the conventional polarization converters. Finally we present a simple fabrication procedure of this newly proposed structure, where the thickness of the residual InGaAsP layer is controlled precisely by using a thin etch-stop layer.

Chemical sensors are one of the oldest fields of research closely related to the semiconductor technology. From the Ion-Sensitive Field-Effect Transistors (ISFET) in the 70's, through Micro-Electro-Mechanical-System (MEMS) sensors from the end of the 80's, chemical sensors are combining in the 90's MEMS technology with LSI intelligence to devise more selective, sensitive and autonomous devices to analyse complex mixtures. A brief history of chemical sensors from the ISFET to the nowadays LSI integrated sensors is first detailed. Then the states-of-the-art of LSI integrated chemical sensors and their wide range of applications are discussed. Finally the authors propose a brand-new usage of integrated wireless MEMS sensors for remote surveillance of chemical substances, such as food-industry or pharmaceutical products, that are stored in closed environment like a bottle, for a long period. In such environment, in-situ analyse is necessary, and electrical cables, for energy supply or data transfer, cannot be used. Thanks to integrated MEMS, an autonomous long-term in-situ quality deterioration tracking system is possible.

We present an 88 wavelength-routing switch (WRS) that monolithically integrates tunable wavelength converters (TWCs) and an 88 arrayed-waveguide grating. The TWC consists of a double-ring-resonator tunable laser (DRR TL) allowing rapid and stable switching and a semiconductor-optical-amplifier-based optical gate. Two different types of dry-etched mirrors form the laser cavity of the DRR TL, which enable integration of the optical components of the WRS on a single chip. The monolithic WRS performed 18 high-speed wavelength routing of a non-return-to-zero signal at 10 Gbit/s. The switching operation was demonstrated by simultaneously using two adjacent TWCs.

The uni-traveling-carrier photodiode (UTC-PD) is an innovative PD that has a unique operation mode in which only electrons act as the active carriers, resulting in ultrafast response and high electrical output power at the same time. This paper describes the features of the UTC-PD and its excellent performance. In addition, UTC-PD-based optoelectronic devices integrated with various elements, such as passive and active devices, are presented. These devices are promising for various applications, such as millimeter- and submillimeter-wave generation up to the terahertz range and ultrafast optical signal processing at data rates of up to 320 Gbit/s.

We achieved first dynamic all-optical signal processing with a bandgap-engineered MZI SOA all-optical switch. The wide-gap Selective Area Growth (SAG) technique was used to provide multi-bandgap materials with a single step epitaxy. The maximum photoluminescence (PL) peak shift obtained between the active region and the passive region was 192 nm. The static current switching with the fabricated switch indicated a large carrier induced refractive index change; up to 14 π phase shift was obtained with 60 mA injection in the SOA. The carrier recovery time of the SOA for obtaining a phase shift of π was estimated to be 250-300 ps. A clear eye pattern was obtained in 2.5 Gbps all-optical wavelength conversion. This is the first all-optical wavelength conversion demonstration with a bandgap-engineered PIC with either selective area growth or quantum-well intermixing techniques.

A uni-traveling-carrier refracting-facet photodiode, a short-stab bias circuit, and a patch antenna are monolithically integrated to make a compact and low-cost photonic millimeter-wave emitter for fiber-radio applications. The device emits the maximum effective radiation power of 173 dBm at 60 GHz including a directive gain of the patch antenna.

In this paper we present a complete methodology for efficient electro-mechanical characterization of a CMOS compatible MEMS technology. Using an original test structure, the so-called "U-shape cantilever beam," we are able to determine all mechanical characteristics of force sensors constituted with elementary beams in a given technology. A complete set of electro-mechanical relations for the design of Microsystems have also been developed.