Chip-based self-referencing using integrated lithium niobate waveguides
Abstract
The measurement and stabilization of the carrier–envelope offset frequency f C E O via self-referencing is paramount for optical frequency comb generation, which has revolutionized precision frequency metrology, spectroscopy, and optical clocks. Over the past decade, the development of chip-scale platforms has enabled compact integrated waveguides for supercontinuum generation. However, there is a critical need for an on-chip self-referencing system that is adaptive to different pump wavelengths, requires low pulse energy, and does not require complicated processing. Here, we demonstrate efficient f C E O stabilization of a modelocked laser with only 107 pJ of pulse energy via self-referencing in an integrated lithium niobate waveguide. We realize an f - 2 f interferometer through second-harmonic generation and subsequent supercontinuum generation in a single dispersion-engineered waveguide with a stabilization performance equivalent to a conventional off-chip module. The f C E O beatnote is measured over a pump wavelength range of 70 nm. We theoretically investigate our system using a single nonlinear envelope equation with contributions from both second- and third-order nonlinearities. Our modeling reveals rich ultrabroadband nonlinear dynamics and confirms that the initial second-harmonic generation followed by supercontinuum generation with the remaining pump is responsible for the generation of a strong f C E O signal as compared to a traditional f - 2 f interferometer. Our technology provides a highly simplified system that is robust, low in cost, and adaptable for precision metrology for use outside a research laboratory.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jun 12, 2020
- Source ID
- 10.1364/optica.392363
Entities
People
- Alexander L. Gaeta
- Bok Young Kim
- Boris Desiatov
- Marko Loncar
- Mengjie Yu
- Tobias Hansson
- Yoshitomo Okawachi
Organizations
- Air Force Office of Scientific Research
- Defense Advanced Research Projects Agency
- National Science Foundation
- Swedish Research Council