Enhanced surface emission in terahertz quantum cascade lasers using plasma layer assisted photonic crystal waveguides
Introduction:Surface-emitting terahertz quantum cascade lasers (THz QCLs) are highly promising for applications requiring high-quality far-field beams and controlled beam divergence. However, limited brightness and output power in conventional surface-emitting designs remain significant barriers to...
Saved in:
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Frontiers Media S.A.
2025-06-01
|
| Series: | Frontiers in Photonics |
| Subjects: | |
| Online Access: | https://www.frontiersin.org/articles/10.3389/fphot.2025.1614809/full |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1849422469348196352 |
|---|---|
| author | Mingxi Chen Mingxi Chen Tsung-Tse Lin Tsung-Tse Lin Li Wang Hideki Hirayama Chiko Otani Chiko Otani |
| author_facet | Mingxi Chen Mingxi Chen Tsung-Tse Lin Tsung-Tse Lin Li Wang Hideki Hirayama Chiko Otani Chiko Otani |
| author_sort | Mingxi Chen |
| collection | DOAJ |
| description | Introduction:Surface-emitting terahertz quantum cascade lasers (THz QCLs) are highly promising for applications requiring high-quality far-field beams and controlled beam divergence. However, limited brightness and output power in conventional surface-emitting designs remain significant barriers to practical implementation. Although photonic crystal structures and distributed Bragg reflectors have been explored to enhance surface emission, intrinsic limitations in emission area scaling and brightness improvement persist. Thus, new strategies are essential to advance the performance of surface-emitting THz QCLs.Methods:This study proposes a plasma-assisted photonic crystal waveguide design to improve surface emission efficiency in THz QCLs. A three-dimensional TM-mode coupled wave theory (3D TM-mode CWT) model was developed, incorporating effective permittivity enhancement and a self-consistent iterative scheme to accurately simulate optical field distribution and interaction within the structure.Results:Simulations reveal that the introduction of a plasma layer effectively disrupts the optical field symmetry characteristic of conventional double-metal waveguides, promoting vertical emission. Through systematic optimization, a plasma layer thickness of 0.8 μm was identified as having the potential to achieve surface emission efficiencies exceeding those of conventional structures by over two orders of magnitude. This enhancement is realized without significantly increasing fabrication complexity.Discussion:The plasma-assisted photonic crystal waveguide design offers a viable pathway toward realizing high-brightness surface-emitting THz QCLs. Although challenges such as material growth control and thermal management remain, the substantial improvement in surface emission efficiency underscores the potential of this approach for future high-performance terahertz applications. |
| format | Article |
| id | doaj-art-eae4aed7467e46e18caef049734a437f |
| institution | Kabale University |
| issn | 2673-6853 |
| language | English |
| publishDate | 2025-06-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Photonics |
| spelling | doaj-art-eae4aed7467e46e18caef049734a437f2025-08-20T03:31:06ZengFrontiers Media S.A.Frontiers in Photonics2673-68532025-06-01610.3389/fphot.2025.16148091614809Enhanced surface emission in terahertz quantum cascade lasers using plasma layer assisted photonic crystal waveguidesMingxi Chen0Mingxi Chen1Tsung-Tse Lin2Tsung-Tse Lin3Li Wang4Hideki Hirayama5Chiko Otani6Chiko Otani7Terahertz-Wave Research Group, RIKEN Center for Advanced Photonics, Sendai, JapanDepartment of Physics, Graduate School of Science, Tohoku University, Sendai, JapanTerahertz-Wave Research Group, RIKEN Center for Advanced Photonics, Sendai, JapanResearch Institute of Electrical Communication, Tohoku University, Sendai, JapanTerahertz-Wave Research Group, RIKEN Center for Advanced Photonics, Sendai, JapanTerahertz-Wave Research Group, RIKEN Center for Advanced Photonics, Sendai, JapanTerahertz-Wave Research Group, RIKEN Center for Advanced Photonics, Sendai, JapanDepartment of Physics, Graduate School of Science, Tohoku University, Sendai, JapanIntroduction:Surface-emitting terahertz quantum cascade lasers (THz QCLs) are highly promising for applications requiring high-quality far-field beams and controlled beam divergence. However, limited brightness and output power in conventional surface-emitting designs remain significant barriers to practical implementation. Although photonic crystal structures and distributed Bragg reflectors have been explored to enhance surface emission, intrinsic limitations in emission area scaling and brightness improvement persist. Thus, new strategies are essential to advance the performance of surface-emitting THz QCLs.Methods:This study proposes a plasma-assisted photonic crystal waveguide design to improve surface emission efficiency in THz QCLs. A three-dimensional TM-mode coupled wave theory (3D TM-mode CWT) model was developed, incorporating effective permittivity enhancement and a self-consistent iterative scheme to accurately simulate optical field distribution and interaction within the structure.Results:Simulations reveal that the introduction of a plasma layer effectively disrupts the optical field symmetry characteristic of conventional double-metal waveguides, promoting vertical emission. Through systematic optimization, a plasma layer thickness of 0.8 μm was identified as having the potential to achieve surface emission efficiencies exceeding those of conventional structures by over two orders of magnitude. This enhancement is realized without significantly increasing fabrication complexity.Discussion:The plasma-assisted photonic crystal waveguide design offers a viable pathway toward realizing high-brightness surface-emitting THz QCLs. Although challenges such as material growth control and thermal management remain, the substantial improvement in surface emission efficiency underscores the potential of this approach for future high-performance terahertz applications.https://www.frontiersin.org/articles/10.3389/fphot.2025.1614809/fullterahertz quantum cascade lasers (THz QCLs)surface-emitting lasersphotonic crystal waveguidesplasma-assisted waveguide designcoupled wave theory |
| spellingShingle | Mingxi Chen Mingxi Chen Tsung-Tse Lin Tsung-Tse Lin Li Wang Hideki Hirayama Chiko Otani Chiko Otani Enhanced surface emission in terahertz quantum cascade lasers using plasma layer assisted photonic crystal waveguides Frontiers in Photonics terahertz quantum cascade lasers (THz QCLs) surface-emitting lasers photonic crystal waveguides plasma-assisted waveguide design coupled wave theory |
| title | Enhanced surface emission in terahertz quantum cascade lasers using plasma layer assisted photonic crystal waveguides |
| title_full | Enhanced surface emission in terahertz quantum cascade lasers using plasma layer assisted photonic crystal waveguides |
| title_fullStr | Enhanced surface emission in terahertz quantum cascade lasers using plasma layer assisted photonic crystal waveguides |
| title_full_unstemmed | Enhanced surface emission in terahertz quantum cascade lasers using plasma layer assisted photonic crystal waveguides |
| title_short | Enhanced surface emission in terahertz quantum cascade lasers using plasma layer assisted photonic crystal waveguides |
| title_sort | enhanced surface emission in terahertz quantum cascade lasers using plasma layer assisted photonic crystal waveguides |
| topic | terahertz quantum cascade lasers (THz QCLs) surface-emitting lasers photonic crystal waveguides plasma-assisted waveguide design coupled wave theory |
| url | https://www.frontiersin.org/articles/10.3389/fphot.2025.1614809/full |
| work_keys_str_mv | AT mingxichen enhancedsurfaceemissioninterahertzquantumcascadelasersusingplasmalayerassistedphotoniccrystalwaveguides AT mingxichen enhancedsurfaceemissioninterahertzquantumcascadelasersusingplasmalayerassistedphotoniccrystalwaveguides AT tsungtselin enhancedsurfaceemissioninterahertzquantumcascadelasersusingplasmalayerassistedphotoniccrystalwaveguides AT tsungtselin enhancedsurfaceemissioninterahertzquantumcascadelasersusingplasmalayerassistedphotoniccrystalwaveguides AT liwang enhancedsurfaceemissioninterahertzquantumcascadelasersusingplasmalayerassistedphotoniccrystalwaveguides AT hidekihirayama enhancedsurfaceemissioninterahertzquantumcascadelasersusingplasmalayerassistedphotoniccrystalwaveguides AT chikootani enhancedsurfaceemissioninterahertzquantumcascadelasersusingplasmalayerassistedphotoniccrystalwaveguides AT chikootani enhancedsurfaceemissioninterahertzquantumcascadelasersusingplasmalayerassistedphotoniccrystalwaveguides |