Jean-Philippe Gouy

InP photodetectors for millimeter-wave applications

We analyze waveguide InP photodetectors for millimeter wave applications. We start with the PIN waveguide photodetector pointing out key problems like optical coupling, microwave access and maximum available power. To benefit form an internal gain we introduce the waveguide InP heterojunction phototransistor showing its ability to operate up to 60 GHz.

Edge-coupled InGaAs/InP phototransistors for microwave radio fibre links

Currently, several ways are investigated concerning pico-cellular systems. Although optical feeding of base stations is involved, there are a lot of microwave signal transmission or generation schemes. Depending on the used scheme, the receiver will behave differently, either as a pure optoelectronic transceiver (microwave transmission) either as a non-linear optoelectronic system (optical microwave generation, optical locking of microwave oscillator, ...). In these fields, we present the work that we did on promising devices, i.e. InP/InGaAs edge-coupled heterojunction phototransistors in twoand three-terminal configuration. Three parts of this paper report modelling tools, device technology and characterization. Modelling tools include optical as well as optoelectronic modelling. A brief description of technological work follows. The characterization is carried out in terms of static response, frequency response and non-linear behaviour.

InP photodetectors for millimeter wave applications based on edge- coupled heterojunction phototransistors

In this paper, we present first experimental results obtained on two 1 and three terminal edge-coupled InP/InGaAs heterojunction phototransistors showing that these devices seem very promising for microwave and millimeter wave applications.

Narrow bandwidth matching of microwave photodetectors

We report on theoretical and experimental studies on the microwave passive reactive matching of high speed photodetectors. Such matching networks can substantially improve the power transfer of a microwave optical link. As an example, we relate two demonstrations which have been made, at a central frequency of 2 GHz, using both commercially available pigtailed PIN photodiode and laboratory made MSM detector. In both cases, matching networks are fabricated using transmission lines and comparison with unmatched devices is made in order to determine the improvement of the power transfer. Trade-offs between working frequency, bandwidth and available improvement in power transfer are presented taking into account parasitics value and the intrinsic capacitance of the detector. The extent of such a matching scheme to monolithic integration in order to increase either working frequency or power improvement is also reported as conclusion.