Development of Test Hardware with Optomechanical Alignment for 200Gbps free space TOSA/ROSA

Abstract

As parallel optical data rates are increasing from tens of Gbps to twenty-five Gbps and beyond[2], Vertical cavity surface emission lasers(VCSELs) and Photo Detectors(PDs) are evolving to accommodate these bandwidths as more channels are being accommodated in a small form factor, there is a need to maintain the coupling efficiency and the performance of the system as the tolerance become tighter due to accommodating channels, To overcome the issues regarding the alignment of these small Optical Modules handling huge amounts of data we require a Mechanical Optical Interface(MOI) which should be capable of handling the tolerance up to tens of microns. This paper describes a small form factor high-speed optical interconnect module called LightKonnectTM built in-house that is capable of up to 192Gbps with 12 channels, having very minute dimensions of 7.0mmx4.9mmx2.76mm±0.lmm. The developed MOI is a custom design prototype to test LightKonnectTM Transmitter(LKTM TX) and LightKonnectTM Receiver (LKTM RX) by a loopback test. This MOI provides a base for a mountable Dove Prism and is capable to provide freedom to the prism in XYZ directions for alignment tolerance of 50 microns, which is tested for the efficient coupling between the VCSEL TOSA(Transmitter optical subassembly)(LKTM TX) and PD ROSA(Receiver optical subassembly)(LKTM RX) which results for the alignment of 12 channels from transmitter to receiver, with maximum coupling performance and low BER for each channel.