Abstract
Miniaturization has been an everlasting theme in the development of semiconductor lasers. One important breakthrough in this process in recent years is the use of metal-dielectric composite structures that made truly subwavelength lasers possible. Many different designs of metallic cavity semiconductor nanolasers have been proposed and demonstrated. In this article, we will review some of the most exciting progresses in this newly emerging field. In particular, we will focus on metallic-cavity nanolasers with volume smaller than wavelength cubed under electrical injection with emphasis on high-temperature operation. Such devices will serve as an important component in the future integrated nanophotonic systems due to its ultra-small size. Semiconductor nanolasers based on subwavelength-scale metal cavities could become important light sources for integrated optical circuitry on silicon. In this paper, Kang Ding and Cun-Zheng Ning from Arizona State University in the USA review progress in this exciting and rapidly evolving field. They cover the achievement of milestones such as the reduction of cavity sizes to below the scale of one wavelength, operation at room temperature, continuous-wave emission and the use of electrical injection. They describe the design and operating principles of nanolasers, as well as the challenges faced in terms of device fabrication, overcoming cavity loss, high-temperature operation and waveguide integration. Future improvements in fabrication technology to address issues such as surface passivation and material deposition will bring further advances in device performance.
Highlights
The field of semiconductor lasers has experienced several paradigm shifts since the first demonstration exactly 50 years ago.[1,2] Each paradigm shift was made possible by new laser designs, new gain materials or structures made available, and the development of necessary fabrication technologies
Representative examples of these paradigm shifts include the transitions from the original p–n junction lasers to double heterostructure lasers, from double heterostructure to quantum well and quantum dot lasers, from Fabry–Perot lasers to distributed feedback lasers and vertical cavity surface emitting lasers (VCSELs), and from VCSELs to photonic crystal lasers, and to various micro-cavity lasers
The size of the smallest metallic cavity nanolaser is already comparable to state-of-the-art electronic transistors in at least one dimension
Summary
The field of semiconductor lasers has experienced several paradigm shifts since the first demonstration exactly 50 years ago.[1,2] Each paradigm shift was made possible by new laser designs, new gain materials or structures made available, and the development of necessary fabrication technologies. Any remaining doubt about metallic structures quickly disappeared after the first experimental demonstration of lasing in near infrared wavelengths by Hill et al.[9] It is interesting to note that micro-cavity lasers and nanolasers prior to 2007 were exclusively based on pure-dielectric cavities, while all the nanolasers after 2007 have metallic structures as essential parts of the cavities Such new paradigm shift has resulted already in many novel devices with improved performance. These results prove that optical gain from semiconductor is capable of compensating for loss in metals in the visible wavelength Noginov and his collaborators investigated possibility of lasing based on the idea of spaser[20] around the wavelength range of 531 nm using nanoparticles of 44 nm diameter with a 14 nm-diameter gold core and dye doped silica shell.[21] The localized surface plasmon oscillation of the gold nanoparticle was sustained by the presence of dye molecules and out-coupled to the photonic mode to be detected.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.