Modeling of MEMS tunable optoelectronic device mirror

The rapid growth of data communication requires more information to be sent through the existing fiber system. This demand can be met using WDM. However, such systems will require many different fixed wavelength devices or tunable devices. Surface micromachined tunable optoelectronic devices provide a potentially low-cost solution for WDM transmitting/receiving systems. To optimize optical performance and tunability of devices, a highly reflecting tunable mirror is needed. Among the materials which are commonly used, AlO/sub x//GaAs possesses the largest refractive index contrast. This huge contrast will achieve a higher reflectance and greater bandwidth with a smaller number of DBR pairs when compared to other material combinations. We previously reported a new type of top DBR mirror using AlO/sub x//GaAs which also has a lower tuning voltage. The design issues of this new mirror structure are discussed. Two different top membrane structures were fabricated and their performance compared.