title: Ultrahigh-speed Si-integrated on-chip laser with tailored dynamic characteristics.
abstract: For on-chip interconnects, an ideal light source should have an ultralow energy consumption per bandwidth (operating en-ergy) as well as sufficient output power for error-free detection. Nanocavity lasers have been considered the most ideal for smaller operating energy. However, they have a challenge in obtaining a sufficient output power. Here, as an alternative, we propose an ultrahigh-speed microcavity laser structure, based on a vertical cavity with a high-contrast grating (HCG) mirror for transverse magnetic (TM) polarisation. By using the TM HCG, a very small mode volume and an un-pumped compact optical feedback structure can be realised, which together tailor the frequency response function for achieving a very high speed at low injection currents. Furthermore, light can be emitted laterally into a Si waveguide. From an 1.54-μm optically-pumped laser, a 3-dB frequency of 27 GHz was obtained at a pumping level corresponding to sub-mA. Using measured 3-dB frequen-cies and calculated equivalent currents, the modulation current efficiency factor (MCEF) is estimated to be 42.1 GHz/mA1/2, which is superior among microcavity lasers. This shows a high potential for a very high speed at low injection currents or avery small heat generation at high bitrates, which are highly desirable for both on-chip and off-chip applications.
authors.affiliation: Department of Photonics Engineering (DTU Fotonik), Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark.
authors.forename: Gyeong Cheol
authors.initials: GC
authors.lastname: Park
authors.affiliation: Department of Photonics Engineering (DTU Fotonik), Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark.
authors.forename: Weiqi
authors.initials: W
authors.lastname: Xue
authors.affiliation: Department of Photonics Engineering (DTU Fotonik), Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark.
authors.forename: Molly
authors.initials: M
authors.lastname: Piels
authors.affiliation: Department of Photonics Engineering (DTU Fotonik), Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark.
authors.forename: Darko
authors.initials: D
authors.lastname: Zibar
authors.affiliation: Department of Photonics Engineering (DTU Fotonik), Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark.
authors.forename: Jesper
authors.initials: J
authors.lastname: Mørk
authors.affiliation: Department of Photonics Engineering (DTU Fotonik), Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark.
authors.forename: Elizaveta
authors.initials: E
authors.lastname: Semenova
authors.affiliation: Department of Photonics Engineering (DTU Fotonik), Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark.
authors.forename: Il-Sug
authors.initials: IS
authors.lastname: Chung