Linear and nonlinear optical properties of KNbO3 ridge waveguides

Ridged channel waveguides in KNbO3 were produced using He+ ion implantation, photolithographic masking, and subsequent Ar+ ion sputtering. We investigated the linear and nonlinear optical characteristics of the waveguides. The effective mode indices are derived from the refractive index profiles using the effective index method. The losses are investigated as a function of wavelength and of the geometrical parameters channel width and ridge height. A minimum loss of 2 dB cm(-1) is measured at a wavelength of 0.633 mu m. We investigated the power handling capabilities at visible and near-infrared wavelengths. Second-harmonic generation in these waveguides is studied both theoretically and experimentally with regard to its dependence on the guide fabrication parameters. Phase-matching configurations for blue light second-harmonic generation are evaluated on the basis of the dispersion of the effective mode indices. Overlap integrals are calculated on the basis of the field distributions derived from the refractive index profiles. The minimum effective guide cross section is 25 mu m(2). A continuous-wave second-harmonic output power of 14 mW at 438 nm was obtained with an in-coupled fundamental power of 340 mW in a 0.73 cm long waveguide, yielding a normalized internal conversion efficiency of 25% W-1 cm(-2) (13% W-1). This corresponds to an improvement by a factor of 3 compared to the best results reported for KNbO3 waveguides up to now

Comparative study of nonlinear-optical polymers for guided-wave second-harmonic generation at telecommunication wavelengths

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Fabrication And Characterization Of Planar And Channel Waveguides In Hybrid Sol-Gel Systems

We report on linear optical properties of Disperse Red 1 (DR1) doped sol-gel planar and channel waveguides. The refractive index and optical propagation losses of the guiding layer were measured between 0.756 μm and 1.64 μm. In the telecommunications window, the attenuation is dominated by the overtones of the O-H bonds vibration bands. We also report on photobleached channel waveguides. Propagation losses were measured at 1.064 μm as a function of the waveguide width. Attenuation coefficients as low as 1 cm-1 in 4 to 8 μm wide channel waveguides were demonstrated. A good confinement of the light is observed in a 3 hours bleached sample. The suitability of plasma etching as an alternative technique for fabricating channel waveguides is demonstrated. © 2000 SPIE

Low Loss Polymer Waveguides Fabricated By Plasma Etching For Nonlinear-Optical Devices Operating At Telecommunication Wavelengths

Organic materials exhibit large optical nonlinearities and are attractive for parametric interactions, cascading, and wavelength demultiplexing. In poled polymer waveguides figures of merit comparable to inorganic materials were obtained for second-harmonic generation (SHG) at 1.55 μm. To reduce the loss of polymer waveguides used for second-order nonlinear effects at telecommunication wavelengths, materials with low intrinsic absorption between 0.6 and 1.6 μm have to be combined with techniques allowing one to form waveguides with low scattering losses

Importance Of Chromophore Environment On The Near-Infrared Absorption Of Polymeric Waveguides

The near-infrared absorption of two chromophore functionalized polymers and combinations of seventeen different guest chromophores in seven different organic polymer matrices were investigated to assess the effect of chromophore structure and environment on absorption. The near-infrared absorption losses were found to be dramatically larger by as much as 2-3 orders of magnitude in polymer matrices than in solution. Furthermore, the absorption of the long-wavelength tail appears to be related to the glass transition temperature of the polymer matrix that contains the chromophore. These results are interpreted in terms of inhomogeneous broadening. © 2000 Optical Society of America

Polymers For Telecommunication Devices Based On Χ\u3csup\u3e2\u3c/sup\u3e:Χ\u3csup\u3e2\u3c/sup\u3e-Cascading

Using polymers in cascading (χ(2):χ(2)) based optical processes at telecommunication wavelengths are envisioned. The key figure of merit is usually [χ(2)(2ω)/α(2ω)]2 where χ(2)(2ω) is the second order nonlinearity α(2ω) is the harmonic loss coefficient. A systematic study of this figure of merit for a series of chromopores in a guest-host system normalized to weight percents of nominally 10% is presented