SBIR Phase I: Athermal Multiplexers Based on Reflective Arrayed Waveguide Grating Devices

Multipass Corporation, Lubbock TX

Investigators

Abstract

DMI-0339012 This Small Business Innovation Research Phase I project proposes to design and demonstrate an athermal multiplexer based on an already existing arrayed waveguide-grating (AWG) device. AWGs are key components in wavelength division multiplexed optical networks. Temperature induced changes in the refractive index of conventional AWGs based on silica-on-silicon technology result in large shifts in the peak wavelength transmission. This necessitates the use of thermoelectric coolers and temperature sensing and compensating circuitry. A specially designed external mirror combined with a reflective AWG (R-AWG), will be used to compensate the temperature-induced index change. Differential thermal expansion of the mirror assembly rotates its reflecting surface at a constant rate with temperature. The reflective AWG-external mirror combination also allows for wavelength trimming that centers the channel wavelength at the ITU grid. The detailed rotation rate and design of the mirror will be determined by simulation and experiments. The goal of this project is to fabricate a high-performance 40-channel, 100 GHz, passive AWG device insensitive of temperature in the 0-85 degree C range. The work hopes to significantly improve the performance of DWDM-based telecommunication systems. These features hope to make the athermal reflective-AWGs proposed here attractive and commercially competitive when compared to conventional AWGs. The new approach should eliminate complex packaging and processing steps, the need for electric power and external temperature control, resulting in a more robust, easier to use, and considerably less expensive packaged device.