Description

Objective: The objective of the activity is to de-risk a key technology building block for quantum communication sources based on weak coherent states; a high bandwidth laser module. By achieving the desired optical properties using direct modulation at the laserpackage, the need for downstream intensity modulation and phase randomisation can be eliminated. Targeted Improvements: The simplification and reduction of both the size and mass associated with the Quantum source chain. Description: The technical problem to be solved is to reduce the system complexity in sources for quantum key distribution based on weak coherent states. The system output isbased on pulses of light, with bandwidth and extinction ratio the key performance drivers, and furthermore randomised phase may be desirable, which requires additional phase modulation and random number generator. If this intensity modulation and phase randomisation can be achieved by direct modulation on the laser (i.e., gain switching) then these properties can all be achieved with much simpler system design. Of the many existing commercial solutions for high-bandwidth lasers, the long-term operation in gain-switching mode is not generally the design driver, and such devices may not work reliably or achieve the desired randomised phase properties. Therefore, this activity is to investigate different laser options with respect to their performance and reliability when operated inthis particular mode suitable for space-based quantum communications applications. The selection may include different material systems (i.e., different wavelengths of interest), laser structures (e.g., VCSEL Vs DFB), and modulation bandwidths (but at least 2GHz). The lasers shall output a single spatial and polarisation mode and should be in a hermetic package with fibre pigtail. The main task of the activity is (1) to demonstrate reliability in gain-switching mode and (2) to assess radiation susceptibility of the parts.Procurement Policy: C(1) = Activity restricted to non-prime contractors (incl. SMEs). For additional information please go to: http://www.esa.int/About_Us/Business_with_ESA/Small_and_Medium_Sized_En…