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    Critical thoughts on quantum technologies

    A New Era in On-Chip Optical Communication: Quantum Well Nanowire Arrays

    ByThemba Hadebe

    Nov 22, 2023
    A New Era in On-Chip Optical Communication: Quantum Well Nanowire Arrays

    In the ever-evolving landscape of technology, the need for efficient connectivity between processor cores continues to grow. Traditional electrical networks, however, face limitations in terms of latency, bandwidth, and power consumption. This has led researchers on a quest to find a better alternative, ultimately resulting in the emergence of on-chip nanophotonic systems as a promising solution.

    On-chip optical networks harness the power of light for data transmission, offering significant advantages over electrical signals. With its unmatched speed, light can carry large amounts of data through multiplexing technologies. A key component of on-chip optical networks is the miniaturized light sources, such as micro-/nano-scale lasers or light-emitting diodes (LEDs). But most developments in this area have been focused on visible wavelengths using III-nitride material systems.

    However, there have been limited reports on the development of high-speed infrared micro-LEDs at telecommunication wavelengths, which are essential for future advancements in Li-Fi technology, photonic integrated circuits (PICs), and various biological applications.

    Here comes the breakthrough—epitaxial grown In(Ga)As(P)/InP nanowires. These nanowires show great potential for miniaturized LEDs and lasers at telecommunication wavelength ranges. The wide bandgap tunability of these nanowires allows for the integration of multi-wavelength light sources on a single chip using a single epitaxial growth process. This integration opens up possibilities for boosting data transmission capacity through wavelength division multiplexing and multiple-input multiple-output technologies.

    The authors of a recent study published in Opto-Electronic Science have successfully demonstrated the selective-area growth and fabrication of highly uniform p-i-n core-shell InGaAs/InP single quantum well (QW) nanowire array LEDs. These nanowire arrays exhibit strong bias-dependent electroluminescence (EL) covering telecommunication wavelengths ranging from 1.35 to 1.6 μm.

    By studying the EL spectra, the researchers identified two prominent peaks: a long wavelength peak at ~1.5 μm originating from the radial QW and a short wavelength peak at ~1.35 μm resulting from a combined emission from axial and radial QWs. This unique feature of dual peaks in the EL spectrum makes these nanowire LEDs highly promising for applications such as optical coherence tomography and bio-sensing.

    As the bias increases, larger carrier injections fill the energy bands in both QWs, resulting in broadened emission spectra and a shift in the peak wavelength. This tunability further enhances the versatility and potential applications of these quantum well nanowire LEDs.

    The study also explored the role of pitch size in the nanowire array LEDs. By varying the pitch sizes, the researchers observed changes in the peak wavelength of the bias-dependent EL spectra. This finding suggests that the pitch size could be used as a parameter to control and manipulate the optical properties of these nanowire arrays.

    In conclusion, the development of multiwavelength quantum well nanowire array micro-LEDs represents a significant advancement in on-chip optical communication. These nanowires offer the potential for integrating various light sources on a single chip, enabling higher data transmission capacity and opening up new possibilities in the field of nanophotonics. With continued research and development, these nanowires could revolutionize the way we connect and communicate in the future.


    What are quantum well nanowire array micro-LEDs?

    Quantum well nanowire array micro-LEDs are miniature light-emitting diodes (LEDs) that utilize quantum well structures within nanowires to emit light. These micro-LEDs have the ability to emit light at multiple wavelengths, making them ideal for applications in on-chip optical communication.

    How do quantum well nanowire array micro-LEDs work?

    Quantum well nanowire array micro-LEDs work by utilizing the unique properties of quantum wells within nanowires. These quantum wells trap electrons and holes, causing them to recombine and release energy in the form of light. By carefully engineering the properties of the quantum wells, these micro-LEDs can emit light at specific wavelengths.

    What are the advantages of using quantum well nanowire array micro-LEDs in on-chip optical communication?

    Quantum well nanowire array micro-LEDs offer several advantages in on-chip optical communication. They can emit light at multiple wavelengths, allowing for higher data transmission capacity through wavelength division multiplexing. Additionally, their small size and monolithic integration potential make them ideal for compact on-chip applications.

    What potential applications do quantum well nanowire array micro-LEDs have?

    Quantum well nanowire array micro-LEDs have a wide range of potential applications. They can be used in Li-Fi technology, enabling high-speed wireless data communication through light. They also have applications in photonic integrated circuits (PICs) and biological sensing, where their multiwavelength emission and small size make them highly suitable for various sensing and imaging applications.

    (source: Opto-Electronic Science – URL: opto-electronic-science.com)