Electrically induced and tunable photonic band gap in submicron periodically poled lithium niobate

Quasi-periodic self-assembled sub-micrometer ferroelectric bulk domain gratings in Rb-doped KTiOPO4

“…3 These structures are probably the only route to obtain quasi-phase matched (QPM) nonlinear optical interactions exploiting counter-propagating waves such as backward second harmonic generation, 4 mirrorless optical parametric oscillators, 5 and amplifiers. Moreover, they have been proposed as tunable photonic band gaps, 6 and for applications as tunable slow-light structures. 7 Although photolithographic patterning followed by electric field (E-field) poling is the most developed and reliable ferroelectric domain engineering technique to date, it still remains challenging for sub-lm periodicities, since not only is standard photolithography not suitable, but also means to gain accurate control of the lateral domain growth are required, adding complicated processing steps and reducing the yield of the poled structures.…”

Multi-wavelength photonic band gaps based on quasi-periodically poled lithium niobate ordered in Fibonacci sequences

“…The deceasing of domain structure has caught lots of interests for its promising applications, for example the realization mirrorless optical parametric oscillators (OPOs) for coherent and tunable light sources demonstrated in submicron periodically poled KTP [14] . Based on a single chip of sub-micron periodically poled lithium niobate (PPLN), we have proposed a narrow PBG structure which is generated by Bragg scattering [15] . The formation of the gap is due to the contra-directional coupling between two orthogonally polarized states caused by the azimuth angle perturbations between the principal axes.…”