SBIR-STTR Award

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

This Small Business Innovation Research Phase II project will optimize Performance and demonstrate reliability of temperature insensitive silica-based arrayed waveguide grating (AWG) multiplexers developed under SBIR Phase I award. In Phase I we have successfully demonstrated that the temperature sensitivity of silica-based AWGs can be eliminated by a combination of a reflective device with a unique external mirror that rotates with temperature at a constant rate. The rotation of the external mirror compensates for the temperature induced index change of silica waveguides and the resulting peak wavelength shift of individual channels, making the device athermal. This has been accomplished without penalties in the device performance. The goal of Phase II is to develop compact 40-channel, 100 GHz, totally passive athermal AWGs with Gaussian or flattop passband profiles that is manufacturable in large volume. Special attention will be given to the reliability certification of athermal AWGs as specified by Telcordia standards. During Phase II we will distribute reliable prototypes to our partners and potential customers for field tests. The research and development program carried out under this Phase II project will result in robust manufacturing process of reliable athermal AWGs ready for commercialization. This project is focused on producing a highly reliable, temperature insensitive, AWGs based on silica-on-silicon technology. AWGs are planar optical devices that are considered key components in dense wavelength division multiplexed (DWDM) optical Networks. The novel approach to the manufacture of silica based AWGs, relying on high-technology silicon IC foundries, results in high quality devices that are produced at low cost, in high volume, and without a large front-end investment. The innovative design results in complete suppression of the temperature sensitivity of silica based AWGs. This approach eliminates the need for electric power and external temperature control of AWGs, resulting in a more robust, and considerably less expensive device package