RESUMEN
Thermal properties of a lowly Nd(3+)-doped disordered Nd:CNGG crystal have been symmetrically investigated. At room temperature, the specific heat, thermal diffusion coefficient and density were determined to be 0.595 J/g.K, 1.223 mm(2)/s and 4.718 g/cm(3), corresponding the thermal conductivity of 3.43 W/m.K. By measuring the thermal lens at different pump power, the thermal-optical coefficient was calculated to be 9.2x10(-6) K(-1) for the first time to our knowledge. All the thermal properties recovered that this material can be used in the moderate and even high pump power.
Asunto(s)
Láseres de Estado Sólido , Lentes , Diseño Asistido por Computadora , Cristalización/métodos , Diseño de Equipo , Análisis de Falla de Equipo , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
Measurements for photorefractive dynamic properties under polarized light with different luminous intensity and wavelength at 650 nm were performed in calcium-doped strontium barium niobate crystals as a function of the time. Experimental results further validated that the different input luminous intensities influence only the saturated time and photorefractive velocity of the photorefractive crystals. Birefringence experiments suggest that an input luminous intensity oscillatory threshold should exist between 64 mW/cm(2) and 13 mW/cm(2). The dynamic change of refractive index from self-focusing to asymmetric self-defocusing was also measured and regarded as the mutual results of the nonuniform-intensity incidence and positive thermal lens effect, which was validated by a further experiment based on the Michelson interference. Also, oscillation accompanying change in the dynamic indices was analyzed and attributed to the high dielectric effect as well as asymmetric self-defocusing in this investigation.
RESUMEN
A new Doppler-free laser spectroscopy method is demonstrated that employs modulation of the position of a laser beam rather than the commonly used intensity or polarization modulation. The technique is applicable in saturated absorption as well as fluorescence measurements, as is illustrated in experiments on sodium and iodine lines. A particular feature of the method is that Doppler- and background-free fluorescence spectra can be recorded without using intermodulation techniques.
