Second harmonic generation in potassium niobate thin films

Abstract

Green light produced by second harmonic generation has been observed in an epitaxial orthorhombic KNbO3 thin film planar waveguide produced by ion-beam sputter deposition on a (100)-oriented MgO single crystal substrate. A Nd:YLF laser beam, with a wavelength of 1.053 μm and ∼80 ps, 100 MHz pulses under mode-locked operation, was coupled into the waveguide using a rutile prism, and a green light streak 3–4 mm long was seen in the guide. The TM0 mode of the input beam was phase matched to the TE1 mode of the second harmonic for a film thickness of 2300 Å. Second harmonic generation was also observed in a nonwaveguided configuration on thicker (4600–6500 Å) films on both MgO and KTaO3 substrates.

Synthesis of Potassium Niobiate (KNbO3) Thin Films by Low-Temperature Hydrothermal Epitaxy

“…( technological difficulties in forming in them waveguides by ion implantation, diffusion, or ion exchange. 12 The main factors for pursuing thin films in acoustic wave applications are a general miniaturization trend in electronic devices using SAW and BAW elements, 13 and the task of SAW suppliers is to integrate as many external functions as possible into the SAW components. 14 Another important factor in realizing the thin films approach is a possibility of enhancing almost all properties of SAW or BAW devices by designing appropriate film/substrate materials or even multilayered thin film structures.…”

“…For electrooptic applications, thin films of KNbO 3 feature lower driving voltages and higher modulation speeds than bulk single crystals; moreover, they have the potential for monolithic integration . For SHG applications of optical waveguides, utilization of KNbO 3 thin films is preferable over bulk single crystals because of the high cost of KNbO 3 large single crystals and technological difficulties in forming in them waveguides by ion implantation, diffusion, or ion exchange . The main factors for pursuing thin films in acoustic wave applications are a general miniaturization trend in electronic devices using SAW and BAW elements, and the task of SAW suppliers is to integrate as many external functions as possible into the SAW components .…”

Effect of seeding layer on orientation control of potassium niobate thin film by CSD

“…Therefore, we tried to control the orientation of the KN thin films by using a seeding layer, because the orientation of a KN film with the highest electromechanical coupling factor (κ 2 ) was (0 0 1)-direction. The lattice parameters of the orthorhombic unit cell for a perovskite KN at room temperature are, a = 0.5696 nm, b = 0.5721 nm and c = 0.3974 nm, 13 respectively. Therefore, (0 0 1)-or (1 1 1)-oriented lead zirconate titanate (PZT) thin layers and (0 0 1)-oriented PbO layer were used as a seeding layer because of the better lattice misfit (Table 1 and Fig.…”

Sputter Synthesis of Ferroelectric Films and Heterostructures

“…One method involves the use of multiple ion beams, generally produced by broad-beam, high-current ion sources (see Reference 19 for example) where each beam is directed at elemental target materials (e.g., Pb, Zr, and Ti). 25 The IBSD techniques present several advantages over other sputter-deposition methods such as plasma sputtering, namely: (1) independent control of ioncurrent density and energy to tailor the sputtering process and consequent film characteristics; (2) lower pressure during film deposition and minimization of the plasma-substrate interaction, which can produce resputtering of the film, damage, and gas incorporation during film growth; (3) the ability to control film composition by tailoring the deposition of each elemental material; and (4) the ability to produce smoother films due to improved control of the deposition rate combined with the possibility of produc-ing perovskite films at lower substrate temperatures with minimum resputtering effects. 1718 The other technique (single-ion-beam/multitarget [SIBMT]) involves the use of a single broad beam and multiple elemental targets exposed to the single beam via a rotating target holder.…”