Abstract-Gallium Phosphide Nonlinear Photonics

Dalziel J. Wilson, Katharina Schneider, Simon Hoenl, Miles Anderson, Tobias J. Kippenberg, Paul Seidler

https://128.84.21.199/abs/1808.03554

Gallium phosphide (GaP) is an indirect bandgap semiconductor used widely in solid-state lighting. Despite numerous intriguing optical properties---including large χ(2) and χ(3) coefficients, a high refractive index (>3), and transparency from visible to long-infrared wavelengths (0.55−11μm)---its application as an integrated photonics material has been little studied. Here we explore GaP-on-insulator as a platform for nonlinear photonics, exploiting a direct wafer bonding approach to realize integrated waveguides with 1.2 dB/cm loss in the telecommunications C-band (on par with Si-on-insulator). High quality (Q>105), grating-coupled ring resonators are fabricated and studied. We directly observe the Kerr effect in response measurements, and obtain the first experimental estimate of the nonlinear index of GaP at telecommunication wavelengths: n2=1.2(5)×10−17m2/W. We also observe Kerr frequency comb generation in resonators with engineered dispersion. Parametric threshold powers as low as 3 mW are realized, followed by broadband (>100 nm) frequency combs with sub-THz spacing, frequency-doubled combs and, in a separate device, efficient Raman lasing. These results signal the emergence of GaP-on-insulator as a novel platform for integrated nonlinear photonics.

Abstract-Dissipative Kerr solitons in optical microresonators

Tobias J. Kippenberg, , Alexander L. Gaeta, Michal Lipson, Michael L. Gorodetsky,

http://science.sciencemag.org/content/361/6402/eaan8083

Shrinking optical metrology

The ability to generate laser frequency combs—light sources comprising equidistant laser lines spanning a large range of wavelengths—has revolutionized metrology and precision spectroscopy. The past decade has seen frequency combs being generated in optical microresonator circuits, offering the prospect of shifting precision metrology applications from the realm of national laboratories to that of everyday devices. Kippenberg et al. review the development of microresonator-generated frequency combs and map out how understanding and control of their generation is providing a new basis for precision technology.