Raman Lasing and Soliton Mode-Locking in Lithium Niobate Microresonators
Abstract
The recent advancement in lithium-niobite-on-insulator (LNOI) technology is opening up new opportunities in optoelectronics, as devices with better performance, lower power consumption and a smaller footprint can be realised due to the high optical confinement in the structures. The LNOI platform offers both large (2) and (3) nonlinearities along with the power of dispersion engineering, enabling brand new nonlinear photonic devices and applications for the next generation of integrated photonic circuits. However, Raman scattering and its interaction with other nonlinear processes have not been extensively studied in dispersion-engineered LNOI nanodevices. In this work, we characterise the Raman radiation spectra in a monolithic lithium niobate (LN) microresonator via selective excitation of Raman-active phonon modes. The dominant mode for the Raman oscillation is observed in the backward direction for a continuous-wave pump threshold power of 20mW with a high differential quantum efficiency of 46%. We explore the effects of Raman scattering on Kerr optical frequency comb generation. We achieve mode-locked states in an X-cut LNOI chip through sufficient suppression of the Raman effect via cavity geometry control. Our analysis of the Raman effect provides guidance for the development of future chip-based photonic devices on the LNOI platform.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 20, 2020
- Accession Number
- AD1105101
Entities
People
- Alexander L. Gaeta
- Cheng Wang
- Marko Loncar
- Mengji Yu
- Mian Zhang
- Rebecca Cheng
- Yoshitomo Okawachi
Organizations
- Harvard University