Mode switching in Photonic Crystal Surface Emitting Lasers with back reflectors and holes of varying depths

Lang, Ben; Sewell, Phillip D; Vukovic, Ana; Boylan, Karl; Rihani, Samir; Moodie, David; Spalding, Richard; Hattasan, Nannicha; Berry, Graham

Abstract

Recent advancements in photonic crystal surface emitting lasers (PCSELs) have incorporated a reflector at the back of the laser to capture light that would otherwise be lost. However, this addition introduces what we believe to be a new interference phenomena that can affect the collection efficiency and the lasing characteristic of the PCSEL. We observe that in double lattice devices (with holes of two different depths), this interference can cause the laser to shift from lasing on the low-energy side of the photonic bandgap to the high-energy side, resulting in a degradation of device performance. This effect is demonstrated through both numerical simulations and experimental measurements. Additionally, by applying an intuitive analytic model to the underlying mechanism, we identify the key parameters that should be adjusted to mitigate this issue.

Citation

Lang, B., Sewell, P. D., Vukovic, A., Boylan, K., Rihani, S., Moodie, D., Spalding, R., Hattasan, N., & Berry, G. (2025). Mode switching in Photonic Crystal Surface Emitting Lasers with back reflectors and holes of varying depths. Optics Express, 33(17), 35257-35269. https://doi.org/10.1364/OE.568336

• Journal Article Type: Article
• Acceptance Date: Jul 31, 2025
• Online Publication Date: Aug 11, 2025
• Publication Date: Aug 25, 2025
• Deposit Date: Aug 13, 2025
• Publicly Available Date: Aug 13, 2025
• Journal: Optics Express
• Electronic ISSN: 1094-4087
• Publisher: Optical Society of America
• Peer Reviewed: Peer Reviewed
• Volume: 33
• Issue: 17
• Pages: 35257-35269
• DOI: https://doi.org/10.1364/OE.568336
• Public URL: https://nottingham-repository.worktribe.com/output/52834023
• Publisher URL: https://opg.optica.org/oe/fulltext.cfm?uri=oe-33-17-35257&id=575472