<i>In-situ</i> local temperature measurement during three-dimensional direct laser writing

Mueller, Jonathan B.; Fischer, Joachim; Mange, Yatin J.; Nann, Thomas; Wegener, Martin

doi:10.1063/1.4821556

Cited by 72 publications

(47 citation statements)

References 16 publications

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“…Furthermore, a significant [14] or even dominant influence [9] of heat accumulation on the polymerization process in DLW has been proposed. In contrast, very recent in-situ temperature measurements have not revealed a significant heating [15]. Notably, such mechanisms are well established in related areas of laser materialsprocessing [16], yet their influence on DLW has not been unambiguously shown so far.…”

Section: Introductionmentioning

confidence: 87%

Three-dimensional multi-photon direct laser writing with variable repetition rate

Fischer¹,

Mueller²,

Kaschke³

et al. 2013

Opt. Express

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141

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Abstract:We perform multi-photon direct laser writing as a function of laser repetition rate over many orders of magnitude and otherwise unchanged experimental conditions. These new data serve as basis for investigating the influence of different proposed mechanisms involved in the photopolymerization: two-photon absorption, photoionization, avalanche ionization and heat accumulation. We find different non-linearities for high and low repetition rates consistent with different initiation processes being involved. The scaling of the resulting linewidths, however, is neither expected nor found to depend on repetition rate or non-linearity. References and links1. H. B. Sun, S. Matsuo, and H. Misawa, "Three-dimensional photonic crystal structures achieved with two-photonabsorption photopolymerization of resin," Appl. Phys. Lett. 74, 786-788 (1999). 2. S. Kawata, H. B. Sun, T. Tanaka, and K. Takada, "Finer features for functional microdevices," Nature 412, 697-698 (2001). 3. M. Straub and M. Gu, "Near-infrared photonic crystals with higher-order bandgaps generated by two-photon photopolymerization," Opt. Lett. 27, 1824Lett. 27, -1826Lett. 27, (2002

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Section: Introductionmentioning

confidence: 87%

Three-dimensional multi-photon direct laser writing with variable repetition rate

Fischer¹,

Mueller²,

Kaschke³

et al. 2013

Opt. Express

Self Cite

155

141

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“…In order to see whether local sample heating actually occurs, we have used an unconventional approach based on luminescent nanoparticles [14]. These were previously used for temperature measurements, for example, in living cells.…”

Section: Sample Heatingmentioning

confidence: 99%

Reaction Mechanisms and In Situ Process Diagnostics

Mueller

Fischer

Wegener

2016

Three-Dimensional Microfabrication Using Two-Photon Polymerization

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“…[11][12][13][14][15] Heat accumulation at the focus, defi ned by pulse repetition rate and scan speed, is used to increase the productivity of 3D polymerization and makes thermal issues very important and actively debated. [16][17][18] Polarization effects in laser fabrication in 2D and 3D geometries are now explored in polymerization by DLW. [19][20][21] In addition, stimulated-emission-depletion control of 3D focal volume, [22][23][24] orientation of the deposition of self-organized materials, [ 25,26 ] the melting and oxidation of thin fi lms, [ 27 ] laser ablation, [ 28,29 ] …”

Section: Doi: 101002/adom201600155mentioning

confidence: 99%

Nanoscale Precision of 3D Polymerization via Polarization Control

Rekštytė

Jonavičius

Gailevičius

et al. 2016

Advanced Optical Materials

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COMMUNICATIONand as self-organized nanopatterns induced on a surface, [ 30 ] are among other polarization-related phenomena demonstrated recently.The infl uence of beam polarization orientation on laser processing has been thoroughly studied in the cases of conductive and dielectric solid targets. [ 31,32 ] There are known effects of polarization on the scalar parameters of laser-matter interaction, such as absorption coeffi cient and ionization rate. [33][34][35][36] It is also known that heat conduction fl ux (vector) in plasma might be dependent on the direction of the imposed fi eld. [ 37 ] In what follows, these effects are considered in succession: (i) accumulation from multiple pulses, (ii) effects of polarization under high-numerical aperture (NA) focusing, and (iii) the infl uence of the external high-frequency electric fi eld on electronic heat conduction. The latter contribution has not yet been considered in laser fabrication under tight focusing. All these photomodifi cation mechanisms occur simultaneously and affect polymerization, which takes approximately a millisecond for common photoresists [ 38 ] at a >90% voxel overlap at typical writing velocity of 100 µm s -1 for widespread laser 3D nanolithography. [ 39 ] In this paper, a systematic analysis via modeling and experiments is presented in order to reveal polarization effects, their infl uence on the feature size (resolution), and the coupling between thermal gradient and polarization in DLW.To study and demonstrate the polarization effects, 3D suspended resolution bridges at various angles, α , between the linear polarization and scanning direction were fabricated on a glass substrate ( Figure 1 inset in (a); see details in the Experimental Section). The line-width difference was 10%-20% (varying exposure) under typical polymerization conditions for the linearly polarized pulses. The largest width of a 3D bridge was observed when the scan direction was perpendicular to the orientation of linear polarization, α = π / 2 ( E ⊥ v s ). The heightto-width ratio of the suspended lines was dependent on the orientation of linear polarization and changed between 3.07 and 3.44; self-focusing was not present under our experimental conditions. [ 40 ] Detailed analysis of polarization, threshold, and heat accumulation effects, which are all important, are discussed next.For the experimental conditions used, the focal spot diameter (at 1/ e 2 ) can be calculated as d f = 1.22 λ /NA = 898 nm assuming, for simplicity, a Gaussian intensity profi le. However, at such tight focusing it is necessary to use the vectorial Debye theory (specifi cs [ 41 ] can be found in Section A, Supporting Information), which predicts an ellipsoidal focal spot with two lateral cross sections: W l = 790 nm and W s = 572 nm for long and short cross sections, respectively (or 500 and 360 nm at full width at half maximum (FWHM)) for the actual experimental

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In-situ local temperature measurement during three-dimensional direct laser writing

Cited by 72 publications

References 16 publications

Three-dimensional multi-photon direct laser writing with variable repetition rate

Three-dimensional multi-photon direct laser writing with variable repetition rate

Reaction Mechanisms and In Situ Process Diagnostics

Nanoscale Precision of 3D Polymerization via Polarization Control

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