In the version 2 array (v2), the same diameter and geometry top mesas are placed on a large, common 125 μm diameter bottom mesa. The version 1 array (v1) consists of six 24 μm diameter top mesas (etched through the p-DBR) matched to the MCF on top of 30 μm diameter bottom mesas (etched through the n-DBR to the n-contact layer). The arrays were designed for direct butt-coupling to the outer six cores of an MCF provided by OFS, where seven 26 μm diameter graded index cores are arranged in a hexagonal array with 39 μm center-to-center spacing. Two different versions of 6-channel VCSEL arrays were fabricated on the same wafer (separated by ~1 mm) and characterized at RT and 85☌ by CHALMERS University of Technology.
MERLIN PROJECT CALENDAR EUROPEAN FORMAT VERIFICATION
The development and experimental verification of these high speed photonic chipsets is an important step toward the realization of the MERLIN lightwave engines. Additionally we report the development of 6-channel circular PD arrays with a temperature independent 0.6 A/W responsivity and 3dB cut off frequency of around 16 GHz at room temperature for 26μm diameter PDs. Specifically we report the development of 6-channel VCSEL circular arrays with measured 3dB bandwidth >21 GHz (25☌) and >19 GHz (85☌), good uniformity, sub-mA threshold current, high slope efficiency (0.7 W/A) and high output power (8 mW). In what follows we report the project progress on the design, fabrication and testing of low power, high bandwidth circular VCSELs and PD arrays. Module environmental testing to assess performance under space environment constraints.Module functional testing to demonstrate high-speed point to multi-point interconnectivity.Fabrication of fully-packaged and ruggedized multi-core digital transceiver module.The use of the multi-core fiber enables the transmission of 6x optical channels through a single fiber feed-through, which accommodates the development of compact, ruggedized and hermetic transceiver modules. Fabrication of radiation hard multimode multi-core fiber.
MERLIN PROJECT CALENDAR EUROPEAN FORMAT DRIVER
Fabrication of high-speed (25 Gb/s) radiation hard, multi-channel BiCMOS VCSEL driver and TIA integrated circuits.Similar to the VCSELs, PDs are fabricated in 2-D circular array configurations. Fabrication of high speed and extended temperature 850 nm PD circular arrays.VCSELs are integrated in 2-D circular array configuration to enable coupling with multi-core radiation hardened fibers. Fabrication of high-speed and extended temperature 850 nm VCSEL arrays.The MERLIN technical objectives from component to system are: MERLIN is a European research initiative that aims to develop an optical multi-channel transceiver technology for the realization of multi-gigabit on-board connectivity that will hit the right speed, size, power consumption and cost targets of next generation telecom satellite payloads. This technology is expected to introduce flexibility in the architectural design by enabling, for instance to shift the ADC/DAC modules closer to the antenna elements, or to partition the OBP into several equipment as well. ASICs and ADC/DAC modules with fibre optic interfaces will effectively support the bandwidth required to the high-speed links whilst removing any distance limitation and better preserving signal integrity. Especially inter-board and inter-equipment connectivity through optical interconnects is of outmost importance for next generation OBPs. Optical interconnects that employ multimode optical fibre, vertical cavity surface emitting laser (VCSEL) and photo-detector (PD) arrays are now considered the enabling technology which will allow to transfer massive amounts of data between equipment, boards, modules and ASICs, quickly, efficiently and at low cost. Modern telecom satellites incorporate On-Board Processors (OBP) having analogue-to-digital (ADC) and digital-to-analogue converters (DAC) at their inputs/outputs and making use of digital processing to handle hundreds of signals as the amount of information exchanged increases, so do the physical size, mass and power consumption of the interconnects required to transfer massive amounts of data through bulk electric wires. At the same time the new broadband applications increase the bandwidth demands in every part of the network - and satellites are no exception. Satellites accommodate global reach and enable world-wide direct broadcasting by facilitating wide access to the backbone network from remote sites or areas where the installation of ground segment infrastructure is not economically viable. Modern broadband communication networks rely on satellites to complement the terrestrial telecommunication infrastructure.