ESA Intended Invitation To Tender

18.1TT.16


Title: SPACE ASSESSMENT OF OPTICAL AMPLITUDE MODULATORS (SCYLIGHT SL.008) PRIORITY 2
Program ref.: ScyLight
Tender Type: C
Quarter: 181
Tender Status: INTENDED
Price Range: 200-500 KEURO
Budget Ref.: E/0502-01A - ScyLight
Proc. Prop.: DIPC
Special Prov.: DK+FR+DE+IT+NL+CH+GB+IE+AT+LU+CZ+RO+CA+NO
Establishment: ESTEC
Directorate: Directorate Telecom & Integrated Applica
Department: Telecom Technologies,Product&Systems Dep
Division: Technologies and Products Division
Responsible: Schmitt, Dietmar
Products: Satellites & Probes / Optical Communication / Optical Comm BB / Laser sources, modulators
Technology Domains: Optics / Optical Equipment and Instrument Technology / Optical Communications
Industrial Policy Measure: N/A - Not apply
Publication Date: 16-FEB-18

(*) Priority 2 The objective of this activity is to investigate the physical mechanisms that induce a drift of the bias point of an optical amplitude modulator and the implications for operation under space environmental conditions. Countermeasures to minimise such drift of the bias point by material selection, electrical/optical design and/or manufacturing processes shall be developed and validated by environmental test. Targeted Improvements: - Understanding of the environmental effects (e.g., temperature, radiation,charging) impacting the bias point behaviour of optical amplitude modulators. - Verification of countermeasures to minimise drift of the bias pointof amplitude optical modulators. Optical amplitude modulators are used to electrically modulate the intensity of optical communications signals. This functionality is required for both digital optical links (e.g., optical communications between satellites, satellite-ground links) and analogue optical links (e.g., optical handling of microwave signals for intra-satellite optical communications). Many different types of materials can be used to implement an amplitude optical modulator (e.g., lithium niobate, semiconductor, polymer). Independently of the material, most of the optical amplitude modulators are implemented by adjusting the bias point of an interferometric path (typically a Mach-Zehnder interferometer) by means of the electro-optic effect. The exception is electro-absorption modulators in semiconductor material, which, however, are discarded for space applications because currently their optical power handling capability is too low. Therefore, all types of optical amplitude modulators that are suitable for space applications have a common requirement for setting the nominal bias point. Additionally, the bias point needs to be controlled in closed loop to compensate for drifts due to environmental effects (e.g., temperature, radiation, charging). Understanding the physical mechanisms that induce a drift of the bias point and developing countermeasures to minimise such drift by material selection, electrical/optical design and/or manufacturing processes is essential to avoid the use of a closed loop bias point controller, or at least to reduce its complexity. (*) Invitations to tender for activities designated Priority 2 will only be initiated on the explicit request of at least one delegation.