Ultra-Fast 3 Terminal VCSEL (U-VCSEL)

Ziva Corporation in collaboration with UCSB will conduct feasibility study for the concept design of a directly modulated laser with capability of modulation of >40GHz with power dissipation <2mW, with optical output power of ~.5 mW. Our approach is to exploit a three terminal VCSEL structure where the third terminal modulates the optical gain by means of current steering while maintaining the lasing pump current constant. Maintaining the pump current constant during modulation eliminates conventional limits imposed on directly modulated VCSEL speeds and promises to achieve ultra-high speed VCSELs approaching the intrinsic bandwidth ~90 Ghz (fmax) of VCSELs or ~180Gbps. By using a third terminal, the requirements for efficient lasing can be in principle decoupled from requirements imposed by fast modulation (e.g. relaxing modal volume/RC time constant tradeoff). This will be a major breakthrough in the ability to cost effectively directly modulate lasers (even in 2-D arrays) at speeds that have hitherto been only possible by using expensive, bulky and lossy external modulators. The approach is extendable to