Optical Remotely Controlled High Dynamic Sampling – ORCHIDS

This proposal follows a previous REI-DGA project (n° 07.34.014) which demonstrated sucessful technological breakthroughs by using nanotechnologies to enhance photoconductive effect and open access to sampling of large bandwidth signals by optical solutions. We obtained 30 dB State-of-the-Art ON/OFF ratio compared to the best worldwide today results (< 5dB) up to a frequency of 20 GHz . This breakthrough is dealing both with the simplicity of this nano photoswitch itself together with the good level of performances compared to the more conventional electronic ways, thanks to the very low jitter provided by laser sources.
In order to reach the top level sampling performances expected in ORCHIDS, a supplementary step of nano photoswitches design optimization is needed. The choice of the photoconductive semiconducting material is oriented to GaAs because of its high resisitivity and controllable very short carrier lifetime. This implies a 800nm-wavelength optical source use. From REI-DGA 07.34.014, it appears that a good fit between material properties, microwave lines and optical waveguide design can be matched to reach low insertion losses, high Signal-to-Noise Ration (SNR) and Spurious-Free-Dynamic-Range (SFDR), and efficient Effective-Number-Of-Bits (ENOB) at high frequency sampling.
Complementary efforts will be dedicated to the elaboration of a compact mode locked optical source in order to deliver short optical pulses with ultra low jitter, with a simple architecture to ensure low cost development.
This project concerns the nanotechnologies field of research and particularly nanosystems integrating optical functions.
This project is leaded by UPMC/L2E who is epxert in degin, modelling and charactrization of microwave devices under ultrafast optical control with the technological support of IEMN which will grow the LT-GaAs material with carrier lifetime control and the complete device fabrication. THALES Research and Technology will provide an pulsed optical source with high repetition pulse rate, based on homemade mode-locked laser to be matched to the needs of ORCHIDS.