Date of download: 7/9/2016 Copyright © 2016 SPIE. All rights reserved. (a) z-scan of the PTLS signal calculated in the mode-matched configuration for different values of the Rayleigh parameters of the pump field and (b) time dependence of the maximal amplitude of the PTLS signal for different Rayleigh parameters of the pump beam. The calculation is performed using Eqs. and parameters λe=807nm, λp=632nm, Φo=−0.1, t=40s, zp=1cm, L=200cm, ap=0, D=1.41×10−3cm2s−1, and ze=0.1, 1, and 10cm as indicated. Figure Legend: From: Thermal diffusivity measurement using the mode-mismatched photothermal lens method Opt. Eng. 2009;48(4): doi: /

Date of download: 7/9/2016 Copyright © 2016 SPIE. All rights reserved. Time dependence of the PTLS signal from 1-cm column of distilled water, 1-cm column of ethylene glycol, and a 1-cm length solid acrylic plate for time value of <200ms. Figure Legend: From: Thermal diffusivity measurement using the mode-mismatched photothermal lens method Opt. Eng. 2009;48(4): doi: /

Date of download: 7/9/2016 Copyright © 2016 SPIE. All rights reserved. Time dependence of a 1-cm column of water and 1-cm column of ethanol measured for a pump light at 807nm and 24mW of power. The gray solid lines correspond to theoretical fittings of the data using Eqs. ; the parameters are λp=632nm, λe=807nm, zp=3000cm, ze=0.12cm, ap=0, L=130cm, Φo=−0.108, and D=1.41×10−3cm2∕s. For the fitting of ethanol data, we use Φo=−0.28 and D=0.95×10−3cm2∕s. Figure Legend: From: Thermal diffusivity measurement using the mode-mismatched photothermal lens method Opt. Eng. 2009;48(4): doi: /

Date of download: 7/9/2016 Copyright © 2016 SPIE. All rights reserved. (a) z-scan PTLS signal from 1-cm column of distilled water normalized over its maximal value for three different times t=0.2, 0.5, and 3.6s. (b)Normalized z-scan PTLS signal for methanol and water. Figure Legend: From: Thermal diffusivity measurement using the mode-mismatched photothermal lens method Opt. Eng. 2009;48(4): doi: /

Date of download: 7/9/2016 Copyright © 2016 SPIE. All rights reserved. Time dependence of the PTLS signal from a 1-cm column of water using two different focusing lenses (f=11 and 24cm) that result in different Rayleigh parameters of the pump beam (ze=0.12 and 0.04cm as indicated in Fig. ). Figure Legend: From: Thermal diffusivity measurement using the mode-mismatched photothermal lens method Opt. Eng. 2009;48(4): doi: /

Date of download: 7/9/2016 Copyright © 2016 SPIE. All rights reserved. (a) Time dependence of the PTLS signal from a 1-cm column of methanol for sample positions z=0 (solid squares), z=2cm (crossed circles), z=4cm (stars), and z=6cm (down triangles) measured using pump light at 807nm and 24mW of power. (b)Time dependence obtained by dividing the value of the signal over its stationary value for sample positions z=0 (solid squares), z=2cm (crossed circles), and z=3cm (double crosses). Figure Legend: From: Thermal diffusivity measurement using the mode-mismatched photothermal lens method Opt. Eng. 2009;48(4): doi: /

Date of download: 7/9/2016 Copyright © 2016 SPIE. All rights reserved. Probe and pump beam radii as a function of the position z measured using a CCD camera. For the pump, we use two different lenses with focal lengths 11 and 24cm. The solid lines are the Gaussian fitting of the experimental data from which Rayleigh parameters can be estimated. Figure Legend: From: Thermal diffusivity measurement using the mode-mismatched photothermal lens method Opt. Eng. 2009;48(4): doi: /

Date of download: 7/9/2016 Copyright © 2016 SPIE. All rights reserved. Experimental setup consisting of a pump laser (Ti–sapphire laser), a probe laser (He–Ne), shutter (Sh), mirrors (M1, M2, and M3), lenses (L1, L2, and L3), beamsplitter (B), sample cell, interference filter F, aperture A, semiconductor detector SD, current amplifier (Ampl) and a digital oscilloscope (Osc). Figure Legend: From: Thermal diffusivity measurement using the mode-mismatched photothermal lens method Opt. Eng. 2009;48(4): doi: /

Date of download: 7/9/2016 Copyright © 2016 SPIE. All rights reserved. (a) Time dependence of the PTLS signal in the pulse regime for the mode-matched configuration calculated using Eq. and parameters λe=807nm, λp=632nm, Φo=0.1, t=40s, zp=1cm, ze=1cm, L=200cm, ap=0, D=1.41×10−3cm2s−1, and z=0.8 and 3cm as indicated. Inset: Corresponding z-scan curve. (b)Time dependence of the PTLS signal in the pulse regime for the mode- mismatched configuration calculated using Eq. and parameters λe=807nm, λp=632nm, Φo=0.1, t=40s, zp=100cm, ze=1cm, L=200cm, ap=0, D=1.41×10−3cm2s−1, and z=0 and 3cm. Inset: Corresponding z-scan curve. Figure Legend: From: Thermal diffusivity measurement using the mode-mismatched photothermal lens method Opt. Eng. 2009;48(4): doi: /

Date of download: 7/9/2016 Copyright © 2016 SPIE. All rights reserved. (a) Time dependence of the PTLS signal in the mode-matched experiment for two different positions of the sample. z=1 and 5cm calculated using Eqs.. The rest of the parameters are as in Fig.. (b) Time dependence of the PTLS signal in the mode-mismatched experiment for two different position of the sample cell: z=0 and 5cm calculated using Eqs.. The rest of the parameters are as in Fig.. Figure Legend: From: Thermal diffusivity measurement using the mode-mismatched photothermal lens method Opt. Eng. 2009;48(4): doi: /

Date of download: 7/9/2016 Copyright © 2016 SPIE. All rights reserved. (a) z-scan of the PTLS signal calculated in the mode-mismatched configuration for different values of the Rayleigh parameters of the pump field and (b) time dependence of the maximal amplitude of the PTLS signal for different Rayleigh parameters of the pump beam. The calculation is performed using Eqs. and parameters λe=807nm, λp=632nm, Φo=−0.1, t=40s, zp=4000cm, L=200cm, ap=0, D=1.41×1−3cm2s−1, and ze=0.1, 1 and 10cm as indicated. Figure Legend: From: Thermal diffusivity measurement using the mode-mismatched photothermal lens method Opt. Eng. 2009;48(4): doi: /