Optical Parametric Generation in a Lithium Niobate Microring with Modal Phase Matching

Abstract

The lithium niobate integrated photonic platform has recently shown great promise in nonlinear optics on a chip scale. Here, we report second-harmonic generation in a high-Q lithium niobate microring resonator through modal phase matching, with a conversion efficiency of 1,500% W −1 . Our device also allows us to observe difference-frequency generation in the telecom band. Our work demonstrates the great potential of the lithium niobate integrated platform for nonlinear wavelength conversion with high efficiencies.

Periodically poled thin-film lithium niobate microring resonators with a second-harmonic generation efficiency of 250,000%/W

“…For comparison, Λ for the TM 00 -to-TM 00 conversion is estimated to be ∼2.87 µm. Owing to the experimental feasibility of a large poling period as well as the potential high Q-factor of the pump TE 00 mode [18,32], our work strate-gically focuses on the TE 00 -to-TM 00 SHG conversion utilizing the d 31 coefficient (∼3.2 pm/V) instead of the TM 00 -to-TM 00 conversion utilizing d 33 (∼19.5 pm/V) [46].…”

“…Leveraging the small mode volume and large power enhancement in high quality-factor (Q) optical microcavities [37], highefficiency SHG with low power consumption can be envisioned. In recent decades, cavity-enhanced SHG in LN integrated photonics platform has been reported through the techniques of modal (MPM) [18,38,39], cyclic (CPM) [34,40,41], and quasiphase matching (QPM) [17]. The latter predicts a higher SHG efficiency as it involves two fundamental modes for a larger modal overlap.…”

Ultrabroadband nonlinear optics in nanophotonic periodically poled lithium niobate waveguides

“…These systems allow for densely integrated nonlinear photonic devices, and achieve efficient frequency conversion due to the large field intensities associated with sub-wavelength mode confinement. The current state of the art of χ (2) nanophotonic devices comprise two approaches: modal phasematching using the geometric dependence of the phase-velocity of TE and TM modes [15][16][17], and quasi-phasematching using waveguides with periodically poled χ (2) nonlinearities [1,18]. While modal phasematching has achieved the largest normalized efficiencies to date (13, 000%/W-cm 2 [15]), the waveguide geometry is determined by the conditions in which the phase velocity of the fundamental and second harmonic are matched.…”

Efficient light coupling between an ultra-low loss lithium niobate waveguide and an adiabatically tapered single mode optical fiber

“…In recent years, photonic devices based on LNOI, including waveguides [6,7], microring resonators [1,8], microdisk resonators [9][10][11], and photonic crystal cavities [12,13] have been developed. On-chip functionalities, such as second harmonic generation [13][14][15][16][17][18], electro-optic modulator [3,[19][20][21][22][23], and optical frequency comb [24,25], have experienced rapid progress with the above-mentioned LNOI micro-/nanodevices. Importantly, many integrated on-chip lithium niobate (LN) devices developed recently already feature low propagation losses [6][7][8]10], which is critical for practical applications.…”