Nanoimprinted DWDM laser arrays on indium phosphide substrates

Kristian Smistrup, Jesper Nørregaard, Andrej Mironov, Tobias H. Bro, Brian Bilenberg, Theodor Nielsen, Johan Eriksen, Anil Haraksingh Thilsted, Ole Hansen, Anders Kristensen, Stephen Rishton, ferdous Khan, Mark Emanuel, Young Ma, Yin Zhang

    Research output: Contribution to journalJournal articleResearchpeer-review

    Abstract

    Dense wavelength division multiplexing lasers play a major role in today's long-haul broadband communication. Typical distributed feedback laser cavities consist of long half-pitch gratings in InGaAsP on InP substrates with grating periods of around 240 nm. The lasers include a quarter wavelength shift in the grating, and are single mode with high side-mode suppression. Typically, such lasers are patterned using e-beam lithography (EBL). We present a fabrication method based on patterning by thermal nanoimprint lithography, which is potentially less costly and faster than EBL. Thermal nanoimprint lithography of laser gratings raises two types of challenges: (1) The imprint process itself is delicate due to the mechanical fragility of indium phosphide substrates and the thermal mismatch between the substrate and the silicon stamp. (2) The subsequent processing puts requirements on the imprint resist thickness after patterning, and the alignment between the crystallographic direction of the substrate and the grating pattern. Working laser arrays were produced, with >40 mW optical power and side mode suppression ratios of more than 50 dB in all 12 channels.
    Original languageEnglish
    JournalMicroelectronic Engineering
    Volume126
    Pages (from-to)149-153
    ISSN0167-9317
    DOIs
    Publication statusPublished - 2014

    Keywords

    • Nanoimprint lithography
    • Process integration
    • Distributed feedback lasers
    • DFB
    • Dense wavelength division multiplexing
    • D-WDM

    Cite this

    Smistrup, K., Nørregaard, J., Mironov, A., Bro, T. H., Bilenberg, B., Nielsen, T., Eriksen, J., Thilsted, A. H., Hansen, O., Kristensen, A., Rishton, S., Khan, F., Emanuel, M., Ma, Y., & Zhang, Y. (2014). Nanoimprinted DWDM laser arrays on indium phosphide substrates. Microelectronic Engineering, 126, 149-153. https://doi.org/10.1016/j.mee.2014.07.004