Electro-optical backplane demonstrator with gradient-index multimode glass waveguides for board-to-board interconnection

Abstract

First time an electro-optical circuit board (EOCB) is demonstrated with integrated planar glass multimode waveguides and with optical pluggable line card connectors. The waveguides are patterned inside commercially available thin-glass panels by performing a two-step thermal ion-exchange process. The resulting low-loss multimode waveguides possess a gradient-index profile. The glass waveguide panel is embedded within the layer stack-up of a printed circuit board (PCB) using proven industrial processes. Cut-outs inside the PCB are structured for assembling a pluggable optical connector and receptacle system for connecting optical fiber based waveguides on the line cards to integrated optical waveguides in the backplane. The demonstration platform comprises a standardized sub-rack chassis and five pluggable test cards with pluggable optical connectors and designed for housing optical engines. The test cards support a variety of different data interfaces for bidirectional signal integrity measurements. The evaluated demonstrator system performed with bit error free data transmission at 10.3 Gb/s for the tested wavelengths of 850 and 1310 nm

Large Optical Backplane With Embedded Graded-Index Glass Waveguides and Fiber-Flex Termination

“…Central to the process was the 5-axis pick-and-place assembly equipment by ficonTEC with three translational and two rotational axes with a positional accuracy better than ±1 µm [14]. Ferrule receptacles have been successfully assembled enabling fiber-to-board connectivity as shown in Fig.…”

“…The complete optical link (MT→50/125 GI-MMF→glass waveguide→50/125 GI-MMF→MT) made of the fabricated EOCB backplane and permanent adhesive bonded fiber-flex interfaces was configured to demonstrate the workability of the system, similar to the Pluggable MT ferrule receptacle fiberflex interface of previous work [14]. The fabricated EOCB backplane with area of (700 x 465) mm² containing four glass panels of (143 x 190) mm² was used as the demonstrator platform and fiber-flex interfaces were mounted and fixed using adhesives on both input and output sides of the panels.…”

Electro-optical line cards with multimode polymer waveguides for chip-to-chip interconnects

“…Embedded optical engines with several lane wide (x4, x8, x12, x16) and data rate (up to 28 Gbps per lane) and FPGA packages (up to 28Gbps) with optical pigtail connectors are available in the market with multiple vendors 4 . Moreover, fiber-optic sheets, polymers waveguides and glass waveguides are in development [5][6][7][8][9][10][11] . Optical links need to provide low absorption at the wavelength of interest; low modal dispersion and they need to match optical connector densities with low coupling loss and cross-talk.…”