Integrated Photonics
Mode-Locked Lasers On-a-Chip
Optical frequency synthesizers have a broad range of important applications, both as sources of low-noise microwave signals and as optical frequency combs. A key enabling technology for optical frequency synthesis and microwave generation is the mode-locked laser, which can provide a stable source of optical pulses with intrinsically low timing jitter. Integrating such laser systems onto a chip using silicon photonics will dramatically reduce size and cost, thus increasing the accessibility of this technology for widespread deployment.
The goal of this research effort is to design and fabricate an optical frequency synthesizer within a CMOS-compatible silicon photonics technology platform, in collaboration with Prof. Watts’ group at MIT. This includes fully-integrated femtosecond mode-locked lasers using erbium-doped and thulium-doped gain materials [1-4] (see Fig. 1), octave-spanning supercontinuum generation in silicon waveguides [5], and a frequency-doubling component in silicon for 1f-2f self-referencing.
Fig. 1 Layout of integrated mode-locked laser designed at MIT.
[1] P. T. Callahan, K. Shtyrkova, N. Li, E. S. Magden, P. Purnawirman, C. Baiocco, D. Coolbaugh, E. P. Ippen, M. Watts, and F. Kaertner, “Fully-Integrated CMOS-Compatible Q-Switched Laser at 1.9µm Using Thulium-Doped Al2O3,” inConference on Lasers and Electro-Optics, OSA Technical Digest (online) (Optical Society of America, 2017), paper STh3N.2.
[2] K. Shtyrkova, P. T. Callahan, M. Watts, E. P. Ippen, and F. Kaertner, “Fully-Integrated artificial saturable absorber based on Kerr nonlinearity in silicon nitride,” in Conference on Lasers and Electro-Optics, OSA Technical Digest (online) (Optical Society of America, 2017), paper AF1B.6.
[3] P. T. Callahan, P. Purnawirman, T. N. Adam, G. Leake, D. Coolbaugh, M. Watts, and F. X. Kaertner, “Double-Chirped Bragg Gratings in a Silicon Nitride Waveguide,” in Conference on Lasers and Electro-Optics, OSA Technical Digest (2016) (Optical Society of America, 2016), paper SF1E.7.
[4] C. M. Sorace-Agaskar, P. T. Callahan, K. Shtyrkova, A. Baldycheva, M. Moresco, J. Bradley, M. Y. Peng, N. Li, E. S. Magden, P. Purnawirman, M. Y. Sander, G. Leake, D. D. Coolbaugh, M. R. Watts, and F. X. Kaertner, “Integrated Mode-Locked Lasers in a CMOS-Compatible Silicon Photonic Platform,” in CLEO: 2015, OSA Technical Digest (online) (Optical Society of America, 2015), paper SM2I.5.
[5] N. Singh, M. Xin, D. Vermeulen, K. Shtyrkova, E. S. Magden, P. T. Callahan, N. Li, A. Ruocco, N. Fahrenkopf, D. Coolbaugh, B. Kuo, S. Radic, E. P. Ippen, F. X. Kärtner, and M. Watts, “Octave Spanning Supercontinuum Generation in Silicon from 1.1 μm to Beyond 2.4 μm,” in Conference on Lasers and Electro-Optics, OSA Technical Digest (online) (Optical Society of America, 2017), paper STu4J.7.
