Lithium niobate photonic crystal waveguides: Far field and near field characterisation

Abstract

In this paper, we experimentally investigate photonic crystal waveguides in a X-cut lithium niobate substrate. The transmission response is measured through the ΓM direction of a triangular lattice structure and the results coincide with the theoretical predictions. In addition, a scanning near-field microscope is used in collection mode to map the optical intensity distribution inside the structure putting in evidence the guiding of the light through lines of defects. This study offers perspectives towards lithium niobate tunable photonic crystal devices

The structure and optical properties of Lithium Niobate grown on quartz for photonics application

“…Because of its remarkable linear and nonlinear optical properties, chemical and mechanical stability makes lithium niobate (LN) an attractive host material for application in photonic crystal devices [4]. Moreover LN has high electro-optical coefficient and low optical losses thus offers suitability in optical communication systems, which are widely used for applications in microwave telecommunications, memory units, electro optics, modulators, optical switches, waveguides, beam deflectors, second harmonic generation, surface acoustic waves (SAW) devices, parametric optical converters and data transmission [5][6][7][8][9][10].…”

Superfocusing and Light Confinement by Surface Plasmon Excitation Through Radially Polarized Beam

“…However, the use of such microscope keeps growing during the last 10 years especially due to its ability to make very local detection of the light distribution surrounding very small samples. Thus, quantum dots [3][4][5][6], photonic crystals [7][8][9][10][11][12][13], or nonlinear materials (Raman, fluorescence, ...) [14][15][16][17] are currently characterized thanks to optical near-field microscopes working with conventional tips (coated or uncoated tapered optical fibers). Apertureless nearfield optical microscopes are often used by exploiting the tip effect, also named the "antenna effect", that leads to a large light confinement at the tip apex (see [18] and references therein).…”

Focused ion beam milling of microchannels in lithium niobate

“…Thus, we observe that there is no significant dependence of the material removal rate using the FIB on the surface orientation of LN. Table I shows a list of material removal rates using the FIB reported by various researchers 19,[21][22][23][24][25] for different cuts of LN. The geometry of the structures milled by Lacour et al 19 and Sulser et al 23 is not entirely clear, and hence, there are a range of material removal rates (0.05-0.15 and 0.07-0.22 lm 3 /nC, respectively) that we have inferred from their paper.…”

“…Focused ion beam (FIB) machining is a viable alternative, having been used to machine LN in limited studies in the past. [19][20][21][22][23][24][25] It is perhaps an ideal choice now that its material removal rates have been increased to 0.3 lm 3 /nC and the lower resolution limit has decreased to 100 nm.…”