Advanced Dispersion Engineering of a III-Nitride Micro-Resonator for a Blue Frequency Comb

Abstract:

A systematic dispersion engineering approach is presented toward designing a III-nitride micro-resonator for a blue frequency comb. The motivation for this endeavor is to fill the need for compact, coherent, multi-wavelength photon sources that can be paired with, e.g., the 171Yb+ ion in a photonic integrated chip for optical sensing, time-keeping, and quantum computing applications. The challenge is to overcome the normal material dispersion exhibited by the otherwise ideal (i.e., low-loss and large-Kerr-coefficient) AlGaN family of materials, as this is a prerequisite for bright-soliton Kerr comb generation. The proposed approach exploits the avoided-crossing phenomenon in coupled waveguides to achieve strong anomalous dispersion in the desired wavelength range. The resulting designs reveal a wide range of dispersion response tunability, which is expected to allow access to the near-UV wavelength regime as well. Numerical simulations of the spatio-temporal evolution of the intra-cavity field under continuous-wave laser pumping confirm that such a structure is capable of generating a broadband blue bright-soliton Kerr frequency comb. The proposed micro-resonator heterostructure is amenable to the current state-of-the-art growth and fabrication methods for AlGaN semiconductors. © 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

Citation

Ali Eshaghian Dorche, Doğan Timuçin, Krishnan Thyagarajan, Thomas Wunderer, Noble Johnson, and David Schwartz, "Advanced dispersion engineering of a III-nitride micro-resonator for a blue frequency comb," Opt. Express 28, 30542-30554 (2020)