Diode Lasers Employing Stacked QD Active Regions Formed by Nano-patterning and MOVPE Growth
Abstract
Quantum dot (QD) active regions hold potential for realizing extremely high performance semiconductor diode lasers. Unfortunately, these unique features of ideal QD active layers have not been fully realized to date. The most successful approach to date of forming QDÕs is self-assembly under the StranskiÐKrastanow (SK) growth mode. However, this approach results in a relatively large distribution of QD sizes, leading to significant inhomogeneous broadening of the spectral gain. These issues are most evident for MOVPE-grown InAs SK QDs grown on InP for targeting the telecom C-band. SK QDs inherently form on top of a two-dimensional Òwetting layerÓ, leading to weak electron and hole confinement to the QD, which results in low gain saturation. We have previously developed an alternate, and potentially more controllable, fabrication method for realizing wetting-layer-free QDs on InP employing dense nanoscale diblock copolymer lithography-based nanofabrication and selective quantum dot growth using metalorganic vapor phase epitaxy (MOVPE). The focus of the current proposal is on minimizing the QD size fluctuations to reduce the spectral gain linewidth, as well as stacking the QDs for scaling optical gain. The specific objectives of this project are to 1) Develop MOVPE growth conditions to minimize QD height variations and demonstrate narrow luminescence linewidths, 2) Develop site-selective QD growth methods and top-down fabrication approaches to allow for QD stacking, as a means to scale the optical gain, 3) Employ these techniques to realize higher performance QD lasers emitting in the telecom C-band.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jul 09, 2020
- Source ID
- W911NF2010185
Entities
People
- L. J. Mawst
Organizations
- Army Contracting Command
- United States Army
- University of Wisconsin–Madison