K. Sutter

Optical Second-Harmonic Generation in Single Crystals of Thiosemicarbazide Cadmium Bromide Hydrate (Cd(NH2NHCSNH2)Br2?H2O)

A new nonlinear optical organic-inorganic crystal, thiosemicarbazide cadmium bromide hydrate (TSCCB), with crystal class m has been grown by a temperature-lowering technique (TLT) and a temperature-difference technique (TDT). The crystal structure of TSCCB is reported. Its linear and nonlinear optical properties have been investigated. The highest measured nonlinear optical susceptibility is dmax = 2.8 pm/V.

Photorefractive gratings in the organic crystal 2-cyclooctylamino-5-nitropyridine doped with 7,7,8,8-tetracyanoquinodimethane

Single crystals of the electro-optic compound 2-cyclo-octylamino-5-nitropyridine (COANP) doped with small amounts of 7,7,8,8-tetracyanoquinodimethane (TCNQ) have been shown to be the first organic material exhibiting the photorefractive effect. Measurements of light induced gratings and beam coupling proved that the electro-optic response originates from photocarrier generation, charge separation, and the electro-optic effect driven by the space charge field.

Linear and nonlinear optical properties of 2‐(N‐prolinol)‐5‐nitropyridine

The optical and nonlinear optical properties of 2‐(N‐prolinol)‐5‐nitropyridine (PNP) have been investigated. The refractive indices show strong dispersion and high birefringence in the spectral range from 488 to 1064 nm. At 632 nm the main refractive indices are nx=1.990, ny=1.788, and nz=1.467. The two major nonlinear optical susceptibilities were determined (dyxx=48 pm/V, dyyy=17 pm/V). Angle‐tuned phase‐matched second‐harmonic generation was demonstrated at 1064 nm. Type I noncritical phase matching using the nonlinear optical susceptibility dyxx is predicted for a fundamental wavelength λ=1020 nm.

Linear and nonlinear optical properties of 2-(N-prolinol)-5-nitropyridine (pnp

Abstract 2-(N-prolinol)-5-nitropyridine (PNP) is a nonlinear optical organic material. Its linear and nonlinear optical properties have been investigated. The refractive indices and the orientation of the index ellipsoid were measured in the spectral range from 488 to 1064 nm. The two major nonlinear optical susceptibilities were determined (dyxx = 48 pm/V, dyyy = 17 pm/V). Angle tuned phase-matched second-harmonic generation was demonstrated at 1064 nm. The conditions for noncritical sum frequency generation were calculated.

Molecular crystals for nonlinear optical applications

We give an overview of the current status of research in the field of molecular crystals with respect to frequency-conversion, electro-optic modulation, and photorefractive effects. Applications of organic materials for nonlinear optics will depend on the development of waveguide devices and bulk crystals. Up to now the most advanced integrated optical organic devices use polymers. Thin crystalline films would also be very attractive if suitable techniques for high quality film deposition would become available. Organic molecular beam epitaxy offers new possibilities for fabricating low loss waveguides based on crystalline materials.

Electro-optic effects in organic single crystals

Electro-optic effects in single crystals of 2-cyclooctylamino-5-mitropyridine and 2-(N- prolinol)-5-nitropyridine have been investigated. The measured wavelength dependence of the electro-optic coefficients can be well explained with the quantum-mechanical two-level model. Enhancements of these coefficients near acoustic phonon resonances of up to a factor of 25 were observed when scanning the modulation frequency of the applied electric field. A comparison between measured second-order polarizabilities and electro-optic coefficients revealed that optic phonons may still contribute considerably to the electro-optic effects in the investigated molecular crystals. A simple expression to estimate the limiting values of electro- optic coefficients is proposed and compared with values of known molecular crystals.

Linear And Nonlinear Optical Properties Of 2-Cyclooctylamino-5-Nitropyridine (COANP)

The optical and nonlinear optical properties of 2-cyclooctylamino-5-nitropyridine (COANP) have been investigated. The refractive indices exhibit strong dispersion and a high birefringence (0.15 - 0.3) in the visible. The three main refractive indices at λ = 550nm are na = 1.670, nb= 1.875 and nc= 1.683. Calculations carried out show interesting critical (frequency-doubling of λ = 1064 nm (Nd:YAG laser)) and noncritical phase-matching properties. The nonlinear optical susceptibilities d32 = (32±16) pm/V and d33 = (13.7±2) pm/V were measured.

Nonlinear optical properties of N-(4-nitro-2-pyridinyl)-phenylalaninol single crystals

The linear and nonlinear optical properties of N-(4-nitro-2-pyridinyl)-phenylalaninol (NPPA) single crystals have been investigated. The refractive indices were measured in the visible and near infrared for wavelengths up to 1318 nm. The nonlinear optical coefficients were measured for the second harmonic generation of 1064 and 1318 nm light. The largest coefficient d23 was found to be 31 pm/V. The phase matching conditions for frequency doubling and sum frequency generation are discussed.

Linear And Nonlinear Optical Properties Of 2-(N-Prolinol)-5-Nitropyridine (PNP)

2-(N-prolinol)-5-nitropyridine (PNP) is a nonlinear optical organic material. Its linear and nonlinear optical properties have been investigated. The refractive indices and the orientation of the index ellipsoid were measured in the spectral range from 488 to 1064 nm. At 632 nm the main refractive indices are nx = 1.990, ny = 1.788, nz = 1.467. The two major nonlinear optical susceptibilities were determined (dyxx = 48 pm/V, dyyy = 17 pm/V). Angle tuned phase-matched second-harmonic generation was demonstrated at 1064 nm. The influence of beam walk-oft for the efficiency of this process is discussed. Type I noncritical phase matching using the nonlinear optical susceptibility dyxx is predicted for a fundamental wavelength λ = 1020 nm.