Time-resolved thermal lens measurements of the thermo-optical properties of glasses at low temperature down to 20 K

Abstract

In this work the time resolved thermal lens spectrometry was applied to measure the absolute values of the thermo-optical properties of low silica calcium aluminosilicate and soda lime glasses at low temperatures, in the range between 20 and 300 K. The thermal relaxation calorimetry was used as a complementary technique to determine the specific heat. The results showed a marked decrease of the thermal diffusivity with the temperature rise, with a dependence similar to that of the mean free path ͑ϳT −1 ͒ in the interval between 20 and 70 K, while in the range between 70 and 300 K the dependence was T −͑0.33±0.02͒. The marked variation of the temperature coefficient of the optical path length change with the temperature rise was attributed to the increase in the coefficient of the electronic polarizability. The results also showed that for the aluminosilicate glass the excess in the specific heat correlated to the so-called boson peak occurred at about 17 K, higher than that of soda lime, which occurs at about 12 K. In conclusion, our results showed the ability of the time resolved thermal lens to determine the thermo-optical properties of glasses at low temperatures, bringing possibilities for experiments in a wide range of optical materials.

Microstructuration induced differences in the thermo-optical and luminescence properties of Nd:YAG fine grain ceramics and crystals

“…The behavior presented in Fig. 5 is very different to that displayed by amorphous materials such as soda lime and aluminosilicate glasses, which present a dependence D ϳ T −͑0.33Ϯ0.02͒ in the range of 70-300 K. 20 According to the Debye model, the thermal diffusivity of a solid can be written in terms of the average sound velocity ͑ s ͒ and of the phonon mean free path ͑l ph ͒ …”

“…Indeed, it has been used recently to obtain optical and thermal properties during phase modification of a wide range of materials, including glasses, polymers, ferroelectric media, and liquid crystals. [18][19][20][21][22][23] In this work, we present a comparative study of the thermo-optical properties of Nd:YAG commercial ͑Czochral-ski grown͒ crystals and fine grain ceramics in a wide temperature range ͑90-300 K͒ by the time-resolved TLS. Results have been discussed with the help of time-resolved optical spectroscopy measurements.…”

Probing Intermolecular Interaction through Thermal-Lens Spectroscopy

“…10 Subsequently, many authors used two-color Z-scan techniques and pump-probe experiments to measure TL in different samples. [11][12][13][14] TL spectroscopy is often the preferred analytical tool, particularly for molecular systems with strong absorbance in comparison to fluorescence. The TL studies are also significant in regard to coherent control goals since they have been used as the feedback parameter for nonfluorescing samples.…”

Influence of temperature and excitation procedure on the athermal behavior of Nd3+-doped phosphate glass: Thermal lens, interferometric, and calorimetric measurements

“…In the cw excitation regime, the TL theoretical model provides a simple and analytical expression that links thermo-optical properties of the sample to the time resolved TL transient signal, which is given by [11][12][13][14][15][16][17][18] I͑t͒…”

“…TL spectrometry ͑TLS͒ has been applied to characterize several kinds of materials in a wide temperature range, from 4 to 800 K. [16][17][18][19][20][21] Besides the thermal diffusivity ͑D͒ values, combining the data measured with this method with those by optical interferometry ͑OI͒ ͑Ref. 22͒ and thermal relaxation calorimetry ͑TRC͒, 23 a general picture about the material thermo-optical properties can be obtained, such as the values of ds / dT, k, and .…”