Nanophotonic structures provide nearly arbitrary controls of light, including with nonlinear interactions to modify optical frequency. Moreover, integration of nanophotonics addresses challenging requirements in complex systems for optical metrology. Nanophotonics open up versatile tools for measuring time, transmitting data, identifying chemicals, sensing distance, searching for new physics, and supporting quantum-information science. I will describe the development of nonlinear nanophotonics devices that provide diverse controls of visible light, generate novel broadband laser sources, and enable integration of quantum sensors.
Optical-frequency combs are versatile tools for measuring time, transmitting data, identifying chemicals, sensing distance, and supporting quantum-information science. A new direction is to produce frequency combs through intriguing nonlinear behaviors of light in integrated microresonators. I will discuss experiments with Kerr microresonators that explore exotic regimes of soliton dynamics and applications of these soliton combs.
Non-linear wave mixing in optical microresonators offers new perspectives for the realization of compact optical frequency ‘microcombs’, holding many promising applications. These typically rely on dissipative soliton formation in driven nonlinear passive cavities with anomalous dispersion, yielding a sech pulse shape. Here, we use a genetic algorithm to ‘invert’ the Lugiato-Lefever equation that models these systems, in order to find the optimum arbitrary dispersion profile needed to achieve a microcomb with a targeted spectral shape. We consider several use cases, such as generating near gaussian pulses, or a telecom-optimized microcomb, as well as optimize a dispersive wave position and power.
The fundamental thermally-driven fluctuations of matter, present in all finite temperature systems and described by the fluctuation-dissipation theorem, are responsible for the precision-limiting noise processes of many measurement devices, including Johnson noise in resistors and thermo-mechanical noise in Fabry-Perot cavities. The LIGO interferometer’s noise floor was famously limited by thermo-elastic fluctuations on its mirror coatings. I will present measurements and analysis of thermo-refractive noise in photonic microresonators, examine how this noise sets a fundamental limit for the coherence of Kerr-microresonator optical frequency combs, and present a novel technique for beating this limit using laser cooling.
Optical-frequency combs are versatile tools for measuring time, identifying chemicals, and generating quantum states. A new direction is to produce frequency combs through intriguing nonlinear behaviors of light in Kerr microresonators. Experiments with whispering-gallery-mode and waveguide ring configurations have been highly productive, exploring the formation, properties, and uses of soliton pulses that are the nonlinear eigenstate of the resonator. The soliton’s spectrum is a comb with a repetition frequency given by the free-spectral range of the resonator. Fabry-Perot (FP) cavities with sufficient Kerr nonlinearity also support soliton pulses. I will discuss experiments that probe soliton frequency combs and ultraprecise measurements with FP cavities based on bulk fused silica, optical fiber, and nanofabricated photonic crystal reflectors.
Microresonator frequency combs, or microcombs, provide a new opportunity for ultra-compact and chip-integrated optical and microwave frequency synthesis. A high-Q dielectric microresonator pumped by a continuous wave laser generates a frequency comb (typically 10-1000 GHz mode spacing) via parametric four‑wave mixing. Due to the tight waveguide confinement and high nonlinearity of the integrated-photonics platform, comb generation occurs with only milliwatts of input power. Additionally, precise geometric control of the waveguide dispersion has led to ultra‑broad bandwidth microcombs suitable for f-2f self-referencing. We have leveraged these advances to demonstrate a dual microcomb optical frequency synthesizer that employs inter-locked silicon nitride and silica microcombs. A silicon nitride resonator with 1 THz mode spacing provides an octave-spanning spectra for self-referencing and connection of the 200 THz pump laser to the silicon nitride repetition rate. The mode-spacing of this comb is subsequently phase-locked with a 22 GHz silica comb that provides the countable repetition rate and final link between microwave and optical domains. This dual microcomb system thus forms a backbone in the telecom C-band against which a tunable chip-integrated laser is phase-locked with user-defined frequency at 1 Hz resolution and absolute accuracy. The core elements of this system are fully reversible, and can also be used to generate low-noise microwaves on both short and long timescales.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.