Second harmonic generation in free-standing lithium niobate photonic crystal L3 cavity

Abstract

We report on second harmonic generation in a photonic crystal L3 cavity drilled in a thin self-suspended lithium niobate membrane. The cavity, resonant for the pump beam in the telecom wavelength range, exhibits a quality factor of around 500. Second harmonic generation has been measured with a low power continuous laser. A conversion efficiency of 6.4×10-9 has been estimated with an input coupled power of 53 µW

Multimode nanobeam cavities for nonlinear optics: high quality resonances separated by an octave

“…High conversion efficiency can also be achieved using two high Q modes. In most previous demonstrations [17][18][19][20][21][22][23][24][25][26]42], these two modes were high Q input modes. In this case, the output Fig.…”

“…Recently, Raman lasing in high Q silicon PCCs was demonstrated [6], while the χ (2) processes of second harmonic generation (SHG) and sum frequency generation (SFG) have also been demonstrated in such cavities in III-V semiconductors [17][18][19][20][21][22][23], as well as in other materials such as lithium niobate [24], SiC [25] and Si [26]. However, as described above, the difficulty in engineering cavities with modes that are far apart in frequency has limited the ability to increase the efficiency at low power levels.…”

Selective engineering of cavity resonance for frequency matching in optical parametric processes

“…In recent years, there has been increasing interest in optical parametric processes in high-Q micro-/nano-cavities, which exhibit great potential for dramatically enhancing parametric generation [6][7][8][9][10][11][12][13][14][15][16][17][18][19] . However, their efficiencies rely crucially on frequency matching among the interacting cavity modes, which is generally deteriorated by device dispersion.…”

“…For FWM, a χ (3) nonlinear process, current methods primarily focus on engineering groupvelocity dispersion of the devices 7,8,10,13,14,20 . For SHG, a χ (2) nonlinear process, intermodal dispersion or birefringence is generally employed to mitigate the frequency mismatch 11,12,[15][16][17][18][19] . These methods rely on manipulating material/waveguide dispersion of devices, which collectively shifts the resonance frequencies of all cavity modes by different extents.…”

Design of nanobeam photonic crystal resonators for a silicon-on-lithium-niobate platform

“…Unfortunately, it is far less amenable to microfabrication techniques than silicon, and processes such as dry etching high-quality wavelength scale optical structures are difficult and non-standard. Nonetheless, ion sliced thin films of LN have been developed in the last few years [5][6][7][8][9] to facilitate among other things nanophotonic fabrication, and more recently, high quality chip-scale optical resonators have been demonstrated in these materials [10][11][12][13][14]. In a recent work on mid-infrared modulators, thin-film silicon was wafer-bonded to LN [15].…”