WARF: P140364US01

Thinner Reflector Stacks for Vertical-Cavity Surface-Emitting Lasers


Zhenqiang Ma, Jung-Hun Seo

The Wisconsin Alumni Research Foundation (WARF) is seeking commercial partners interested in developing ultrathin distributed Bragg reflectors for use in high-performance VCSELs.
OVERVIEWDistributed Bragg reflectors (DBRs) are found in photodetectors, solar cells and other optical sensors. Stacks of DBRs are incorporated in vertical-cavity surface emitting lasers (VCSELs), which are a type of compact light source used in a variety of applications, including fiber optic networks.

Slimmer VCSELs are highly desirable but their bulky stacks of DBRs are a problem. Conventional fabrication methods (e.g., epitaxial growth, chemical vapor deposition, etc.) yield DBRs with thick layers, rough surfaces or structural flaws that degrade performance.
THE INVENTIONUW–Madison researchers have developed a method to create ultrathin DBRs that can be used in VCSELs. The DBRs are made of alternating layers of single-crystalline Group IV semiconductors (e.g., silicon or germanium) and silicon dioxide. The single-crystalline layers are incorporated into the stack using a thin film transfer and bonding process, while the silicon dioxide layers can be thermally grown or deposited.

The process results in very thin DBRs that can provide extremely high reflectance.
  • Ultrathin distributed Bragg reflectors for VCSELs
  • Improves laser performance at a fraction of overall device thickness
  • Makes it possible to obtain high quality silicon dioxide
  • Yields precisely controlled/uniform layers
  • Minimizers scattering loss
  • Easier, cheaper manufacturing process
  • No lithography
  • Process supports a wide variety of substrates.
Contact Information
For current licensing status, please contact Jeanine Burmania at or 608-960-9846.
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