Nonlinear Photonics & Integrated Lasers
We generate an integrated high-power Kerr frequency comb in a silicon-nitride resonator via self-injection locking of a high-power multimode gain chip. We generate 27 comb lines with total power exceeding 0.1 W.
A. Gil-Molina, Y. Antman, O. Westreich, X. Ji, M. C. Shin, G. R. Bhatt, B. Y. Kim, Y. Okawachi, A. L. Gaeta, and M. Lipson, "High-Power Fully-Integrated Frequency Comb Generation," in Conference on Lasers and Electro-Optics, Optica Technical Digest (Optica Publishing Group, 2022), paper SF2G.2.
We demonstrate a supercontinuum light source for OCT imaging in a compact 1 mm2 Si3N4 chip. We achieve 105 dB sensitivity and a 6-dB sensitivity roll-off at 1.81 mm with only 300 µW incident power.
We demonstrate a highly efficient integrated laser, with more than 200 mW single mode output, overcoming the tradeoff between high power, efficiency and coherence in traditional lasers. The laser is based on the collapsing of a multimode gain into a single mode via self-injection locking.
Y. Antman, A. Gil-Molina, O. Westreich, X. Ji, A. L. Gaeta, and M. Lipson, "High Power and High Efficiency on-chip Integrated Laser," in Conference on Lasers and Electro-Optics, Optica Technical Digest (Optica Publishing Group, 2022), paper SM2P.2.
Visible Photonics for Emerging Fields
Widely tunable and narrow linewidth lasers at visible wavelengths are necessary for applications such as quantum optics, optical clocks, and atomic and molecular physics. Currently used lasers are benchtop, precluding these technologies from getting outside of research laboratories. Here we demonstrate a chip-scale visible lasers platform that enables tunable and narrow linewidth lasers from near-ultraviolet to near-infrared. By using micrometer-scale silicon nitride resonators and commercial Fabry-Perot laser diodes, we achieve coarse tuning up to 12.5 nm and mode-hop-free fine tuning up to 33.9 GHz with intrinsic linewidths down to a few kHz. In addition, we show fine tuning speeds up to 267 GHz/µs, fiber-coupled powers up to 10 mW and typical side-mode suppression ratios above 35 dB. These specifications of our chip-scale lasers had only been previously achieved by large state-of-the-art benchtop laser systems, making our lasers stand out as powerful tools for the next generation of visible-light technologies.
We demonstrate the first phased array operating at blue wavelengths. We show wide-angle beam steering over a 50° field-of-view with a beam width of less than 0.17° using a high confinement silicon nitride waveguide platform.
2D Material Nanophotonics
We show low insertion loss platform based on loss modulation of hybrid SiN/graphene structure. We measure an intrinsic quality factor of 80,000 in a ring resonator based device when the graphene is in its high loss state.
I. Datta, X. Ji, G. R. Bhatt, B. S. Lee, and M. Lipson, "Low insertion loss, graphene-based platform for loss modulation," in Conference on Lasers and Electro-Optics, Optica Technical Digest (Optica Publishing Group, 2022), paper SM5P.4.
Novel Concepts in Integrated Photonics
We demonstrate the loading of very short optical pulses into a high-Q cavity with linewidth much narrower than the pulse frequency envelope. We show that loading into the cavity is significantly enhanced if the pulse is combined with a cw-field, thus altering the pulse frequency profile to better match the cavity profile.
J. Hinney, U. D. Dave, A. G. Molina, X. Ji, and M. Lipson, "Loading short pulses into long lifetime cavities," in Conference on Lasers and Electro-Optics, Optica Technical Digest (Optica Publishing Group, 2022), paper FM5B.3.
We demonstrate SiN-based passive waveguides with ultra-low thermo-optic effect, based on a novel waveguiding mechanism that confines light in the lower index of refraction. We demonstrate broadband operation over at least 200nm, with less than 0.01% change in the index over 200 degrees.
J. R. Rodrigues, G. R. Bhatt, I. Datta, U. D. Dave, S. Chaitanya, E. Shim, and M. Lipson, "SiN-based waveguides with ultra-low thermo-optic effect," in Conference on Lasers and Electro-Optics, Optica Technical Digest (Optica Publishing Group, 2022), paper SM4G.3.
We demonstrate passive PT symmetry breaking between the spatial modes within a single SOI waveguide with metal deposited directly on top. By leveraging this effect, we show low propagation loss of < 1 dB for a 100 μm long, 10 μm wide waveguide partially covered with 100 nm thick metal.
We demonstrate robust mode conversion up to the 12th higher order mode in silicon waveguides by using an optimized adiabatic directional coupler and using subwavelength waveguides. The conversion efficiency is better than -1.5 dB over a 75 nm bandwidth and tolerating ±30 nm fabrication variations.
Manipulating Mid-IR and Far-IR Light
We demonstrate a single longitudinal mode, tunable mid-IR laser by self-injection locking a multiple longitudinal mode Interband Cascade Laser (ICL) to a high-Q Si microresonator at 3.4 μm.
We demonstrate a platform for heat-to-electricity conversion based on near-field radiative heat transfer. The platform is based on tens-of-μm long suspended micro-heaters at >400˚C, placed <100 nm away from a room temperature photodetector.