Smith, Peter Raymond;
              
      
            
                Papatryfonos, Konstantinos;
              
      
            
                Selviah, David R;
              
      
        
        
  
(2026)
  Optical Waveguide-Pair Design for CMOS-Compatible Hybrid
III-V-on-Silicon Quantum Dot Lasers.
Nanomaterials
      
    
    
    
        
   (In press).
  
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Text
 Selviah_Revised manuscript final version.pdf Access restricted to UCL open access staff until 15 March 2026. Download (1MB)  | 
          
Abstract
The development of compact, energy-efficient integrated lasers operating at 1.3 µm remains a critical focus in silicon photonics, essential for advancing data communications and optical interconnect technologies. This paper presents a numerical study of distributed Bragg reflector (DBR) hybrid III-V-on-silicon lasers, analyzing design trade-offs and optimization strategies based on supermode theory. The III-V section of the design incorporates InAs/(Al)GaAs quantum dots (QDs), which offer improved temperature insensitivity at the cost of more complex III-V/Si optical coupling, due to the high refractive index of (Al)GaAs. Consequently, many current laser designs rely on silicon waveguides with a thickness exceeding 220 nm, which helps coupling but limits their compatibility with standard CMOS technologies. To address this challenge, we perform detailed simulations focusing on 220-nm-thick silicon waveguides. We first examine how the mode profiles jointly depend on the silicon waveguide dimensions and the geometry and composition of the III-V stack. Based on this analysis, we propose a novel epitaxial design that enables effective III-V/Si coupling, with the optical mode strongly confined within the III-V waveguide in the gain section and efficiently transferred to the silicon waveguide in the passive sections. Moreover, the final design is shown to be robust to fabrication-induced deviations from nominal parameters.
| Type: | Article | 
|---|---|
| Title: | Optical Waveguide-Pair Design for CMOS-Compatible Hybrid III-V-on-Silicon Quantum Dot Lasers | 
| Language: | English | 
| Additional information: | This version is the author-accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions. | 
| Keywords: | Silicon Photonics; design methodology; distributed Bragg reflector laser; evanescent coupling; hybrid laser; quantum dot laser; overlap integral; supermode theory; tolerance; trade-off. | 
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science > Dept of Electronic and Electrical Eng  | 
        
| URI: | https://discovery.ucl.ac.uk/id/eprint/10216124 | 
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