G.J.T. Heesink

Novel calixarenes in thin films for efficient second harmonic generation

Calix[4]arenes are a novel type of molecules for nonlinear optics. In a single molecule four pi-conjugated systems are combined. Corona poled guest-host polymer systems [calix[4]arenes-poly(methyl-methacrylate)] with transparency into the UV and loading up to 100% show a high degree of orientation. The maximum resonant d33 nonlinear coefficient measured at a fundamental wavelength of 590 nm is 51 pm/V. The d33 values of the thin films relax after poling to 65% of their maximum value. Results indicate self-organization of the molecules upon poling.

Linear and nonlinear optical properties of substituted pyrrolo[1,2-a]quinolines

Synthesis and characterization of a class of chiral nonlinear optical organic materials viz. pyrrolo[1 with chiral molecular structure are presented. Both single crystals and crystalline thin films of la have been grown. Structural parameters have been determined by X-ray diffraction. Linear and nonlinear optical properties of the crystals have been analyzed. The transparency range extends into the near-UV-region. The nonlinear coefficients djjk have been measured by second harmonic generation (SHG) using the Makerfringe and phase match techniques.

Second harmonic generation of diode laser radiation in KNbO3

Both CW and pulsed diode lasers covering the wavelength region 855-912 nm have been investigated for the frequency doubling in KNbO. The influence of the spectral distribution mode character and the optical geometry of the laser beam have been investigated for several AlGaAs diode lasers. Second harmonic radiation with maximum efficiency of typically 1 has been detected both by temperature tuning CT 10-130 C noncritical phase matching) and by angle tuning. Results clearly demonstrate the critical aspects of the laser mode spectrum and the beam geometry as to the phase matching criterion in frequency doubling.