As reported in Nature Nanotechnology<\/a>, engineers solved this problem by introducing an architecture that decouples electrical injection from optical confinement. This allows electricity to be delivered where it is needed while leaving the light-guiding structure largely undisturbed.<\/p>\n\u201cThis breakthrough could help enable a new generation of compact and energy-efficient photonic technologies,\u201d said principal investigator Boubacar Kant\u00e9, a professor of electrical engineering and computer sciences at UC Berkeley and a faculty scientist at Berkeley Lab. \u201cMore broadly, our approach, which I call orthogonal optoelectronics, enables engineering electrical pathways and optical modes independently, so that each can be optimized without compromising the other.\u201d<\/p>\n
Good optics vs. good electrical injection<\/p>\n
Through this study, researchers set out to find a better way to electrically power extended modes of nanophotonic lasers. These devices use structures smaller than the wavelength of light to control how light is generated, trapped and emitted. They are key to enabling compact, efficient and highly controllable light sources that could ultimately impact many applications.<\/p>\n
The best nanophotonic devices, however, often require strong index contrast, an ongoing challenge according to Emma Martin (Ph.D.\u201925 EECS), co-lead author and formerly a graduate student researcher in the Kant\u00e9 Lab. She explained that this contrast is what allows the device to tightly confine and control light. But to electrically power such a device typically requires the addition of conductive materials or electrical pathways. This can create a problem, since the added materials can disturb the optical design, reduce the refractive-index contrast and degrade the device performance.<\/p>\n
\u201cIn simple terms, we were trying to solve the conflict between \u2018good optics\u2019 and \u2018good electrical injection.\u2019 We wanted to create a structure that could be electrically powered without disturbing the optical cavity that makes the device work,\u201d said Martin. \u201cOur goal was to demonstrate an electrically pumped nanophotonic laser where current can be delivered across an extended optical mode while still preserving the optical advantages of a suspended, high-contrast photonic crystal structure.\u201d<\/p>\n
Nano-posts help unlock a solution<\/p>\n
To achieve the best of both worlds \u2014 good optics and good electrical injection \u2014 the researchers developed a new device design that allows them to inject electricity into a light-trapping structure without disturbing the light.<\/p>\n
According to Md Ishfak Tahmid, co-lead author and a Ph.D. student in the Department of Electrical Engineering and Computer Sciences, the \u201ctrick\u201d is to support the device on an array of nano-posts, which are placed exactly at the spots where the light\u2019s electromagnetic field naturally goes to zero. The nano-posts can then conduct electricity while remaining invisible to the light.<\/p>\n
\u201cUsing this design, we achieved electrically powered lasing at room temperature at the wavelengths used in fiber-optic communications,\u201d said Tahmid. \u201cIt\u2019s the first time current has been delivered uniformly across hundreds of these tiny cells while preserving the optical properties of the underlying photonic structure.\u201d<\/p>\n
According to Tahmid, the nano-posts or other electrical pathways also can be selectively positioned to excite specific optical modes. \u201cThis could lead to highly controlled electrically driven lasers, integrated photonic circuits and devices for quantum photonics,\u201d he said.<\/p>\n
Electrical uniformity through nanofabrication control<\/p>\n
While demonstrating that they can electrically inject current into an extended nanophotonic laser mode while preserving its optical properties, the researchers made an unexpected discovery: Their main limitation was not the optical design, but rather the uniformity of electrical pathways.<\/p>\n
They observed that the optical mode was quite robust even when there were some variations in the nano-post sizes. However, small variations in the nano-posts could strongly affect how uniformly current was injected across the device.<\/p>\n
\u201cThis showed us that when electrical injection is distributed over many nanoscale contact points, fabrication uniformity becomes extremely critical,\u201d said Kant\u00e9. \u201cThis was an important finding because it identifies a new design regime for electrically injected nanophotonic devices. And it means future devices will require close co-design of optics, electronics, heat flow and nanofabrication.\u201d<\/p>\n
Looking ahead, this work could be useful for many technologies that require compact and controllable light sources, including optical communication, data centers for AI, sensing, imaging, LiDAR, on-chip photonic systems and quantum technologies.<\/p>\n
\u201cOur work provides a way to electrically control nanoscale optical states without strongly disturbing them, which is a key requirement for many advanced photonic technologies,\u201d said Kant\u00e9.<\/p>\n
In addition to Kant\u00e9, Martin and Tahmid, co-authors include Hwi-Min Kim, Lory Marchand and Tanveer Ahmed Siddique \u2014 all with the Department of Electrical Engineering and Computer Sciences \u2014 and Scott Dhuey and Adam Schwartzberg with the Molecular Foundry at Berkeley Lab.<\/p>\n
This research was supported by the Office of Naval Research, with partial support by the NSF Quantum Leap Challenge Institutes (QLCI) program, the Bakar Prize and the Berkeley Emerging Technology Research (BETR) Center at UC Berkeley.<\/p>\n","protected":false},"excerpt":{"rendered":"Discovery could lead to a new generation of compact and energy-efficient photonic technologies July 6, 2026 by Marni…\n","protected":false},"author":2,"featured_media":390133,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[34],"tags":[143,145,144],"class_list":["post-390132","post","type-post","status-publish","format-standard","has-post-thumbnail","category-oakland","tag-oakland","tag-oakland-headlines","tag-oakland-news"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/us-ca\/wp-json\/wp\/v2\/posts\/390132","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/us-ca\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/us-ca\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us-ca\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us-ca\/wp-json\/wp\/v2\/comments?post=390132"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/us-ca\/wp-json\/wp\/v2\/posts\/390132\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us-ca\/wp-json\/wp\/v2\/media\/390133"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/us-ca\/wp-json\/wp\/v2\/media?parent=390132"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/us-ca\/wp-json\/wp\/v2\/categories?post=390132"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/us-ca\/wp-json\/wp\/v2\/tags?post=390132"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}