Prototype development of an all optical linear sampling based constellation oscilloscope – OCELOT

The OCELOT project aims at developing the optical linear sampling of very high rate (> 100Gbps) optical signals with advanced modulation formats, especially in phase (x-PSK), in order to extract amplitude and phase information and display it in a constellation diagram. The main purpose of OCELOT is the transfer of this technology from a research industrial laboratory to a SME by realizing the prototype of a future product, which is planned to be launched on the very competitive constellation oscilloscope market.
The two major obstacles identified in the project refer on one hand to the pulse laser source used for linear sampling, on the other hand to the acquisition and processing of the sampled and digitized signals, with display refreshment rate (> 1Hz) matching end users requirements about real time measurement and analysis.
The laser source must provide short (< 1ps), stable (timing jitter < 200fs) pulses, with relatively low average power (> -3dBm) but also low pulse rate (40MHz-300MHz), in order to fit the economical requirement of simple implementation and reduced cost. This source, containing an amplifying quantum dot chip, will be developed in a specific task, with close collaboration of several partners of OCELOT project. The low economical cost is a hard requirement and will be considered as important as the pure technical purposes. After validation, the laser will be transferred to the SME APEX for its integration inside the constellation oscilloscope prototype.
The digital acquisition board (CAN) will be designed with digital signal processing integrated circuits (DSP, FPGA) enabling the end display of the constellation diagram. A robust and fast algorithm must be designed, developed and implemented in FPGA, and transferred to APEX with the CAN for its integration in the prototype.
Then, the prototype, integrating the laser pulse sources, the linear sampling modules, and the digital acquisition and processing boards, will be realized by APEX and validated with the very high rate and diverse format modulation sources developed by partner UR1-ENSSAT. The project will be promoted by presenting the prototype in important scientific and technical international conference exhibitions, in order to probe the market and attract future customers.