Dynamics of the laser heating and oxidation of thin metallic films, allowing for absorptivity variation

Shakhno, E. A.; Nguen, Q. D.

doi:10.1364/jot.83.000219

Cited by 8 publications

(4 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To determine the thickness of the oxide layer H and its distribution over the film surface, we solved Equation (1) using the "equivalent time" method proposed earlier by Libenson, M.N. [35], which had numerous applications in our and other authors' works (for example, [24,[28][29][30][31][32][33][34]) for calculation of the dynamics of oxidation, taking into account the temperature distribution in the film at the heating T heat and cooling T cool stages for each pulse [34]:…”

Section: Setting the Simulation Problemmentioning

confidence: 99%

“…Laser thermochemical recording on thin Ti films requires a rather long (up to ms) exposure to obtain through oxidation due to the feedback complexities of the oxidation process [ 25 , 26 , 27 , 30 , 31 , 32 , 33 , 34 ]. However, in order to avoid the accumulation of heat in the film and its thermal damage, it is preferable to expose the film by several thousand consecutive picosecond pulses with a low repetition rate (around 1000 Hz or lower) [ 34 ].…”

Section: Laser Interference Patterningmentioning

confidence: 99%

“…To determine the thickness of the oxide layer H and its distribution over the film surface, we solved Equation (1) using the “equivalent time” method proposed earlier by Libenson, M.N. [ 35 ], which had numerous applications in our and other authors’ works (for example, [ 24 , 28 , 29 , 30 , 31 , 32 , 33 , 34 ]) for calculation of the dynamics of oxidation, taking into account the temperature distribution in the film at the heating T heat and cooling T cool stages for each pulse [ 34 ]:

where ρ me , c me , ρ ox , c ox , ρ S , and c S are the densities and heat capacities of the metal layer, oxide layer, and substrate, respectively; a S is the substrate thermal diffusivity; h and h me = ( h − H/υ PB ) are the thicknesses of the metal layer before and after laser action; υ PB is the Pilling–Bedworth coefficient, which equals the ratio of the molar volumes of the metal oxide and metal itself, 1.78 for Ti [ 36 ]; T in is the initial film temperature; q ( x ) is the spatial distribution of laser intensity along the transverse coordinate x , which was approximated by a sine function; τ is the laser pulse duration; A(x, H) is the film absorption, which was evaluated for each pulse using the optical matrices method (according to [ 37 ]) depending on the oxide layer thickness at the beginning of the pulse action. The heat transfer characteristic ( γ ) from the film to the substrate corresponds to:

…”

Section: Laser Interference Patterningmentioning

confidence: 99%

See 2 more Smart Citations

Laser Thermochemical High-Contrast Recording on Thin Metal Films

et al. 2020

View full text Add to dashboard Cite

Laser-induced thermochemical recording of nano- and microsized structures on thin films has attracted intense interest over the last few decades due to essential applications in the photonics industry. Nevertheless, the relationship between the laser parameters and the properties of the formed oxide structures, both geometrical and optical, is still implicit. In this work, direct laser interference patterning of the titanium (Ti) film in the oxidative regime was applied to form submicron periodical structures. Depending on the number of laser pulses, the regime of high contrast structures recording was observed with the maximum achievable thickness of the oxide layer. The investigation revealed high transmittance of the formed oxide layers, i.e., the contrast of recorded structures reached up to 90% in the visible range. To analyze the experimental results obtained, a theoretical model was developed based on calculations of the oxide formation dynamics. The model operates on Wagner oxidation law and the corresponding optical properties of the oxide–metal–glass substrate system changing nonlinearly after each pulse. A good agreement of the experimental results with the modeling estimations allowed us to extend the model application to other metals, specifically to those with optically transparent oxides, such as zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb), and tantalum (Ta). The performed analysis highlighted the importance of choosing the correct laser parameters due to the complexity and nonlinearity of optical, thermal, and chemical processes in the metal film during its laser-induced oxidation in the air. The developed model allowed selecting the suitable temporal–energetic regimes and predicting the optical characteristics of the structures formed with an accuracy of 10%. The results are promising in terms of their implementation in the photonics industry for the production of optical converters.

show abstract

Section: Setting the Simulation Problemmentioning

confidence: 99%

Section: Laser Interference Patterningmentioning

confidence: 99%

…”

Section: Laser Interference Patterningmentioning

confidence: 99%

See 1 more Smart Citation

Laser Thermochemical High-Contrast Recording on Thin Metal Films

et al. 2020

View full text Add to dashboard Cite

show abstract

“…To create CGH, the technology of direct laser writing on thin chromium films is widely used [9][10][11][12]. In this regard, reducing the size of the structures formed in chromium films is an urgent task.…”

Section: Introductionmentioning

confidence: 99%

Increasing the spatial resolution of direct laser writing by using a non-Gaussian intensity distribution in the writing laser spot

Kuts

Mandrusova

Sedukhin

et al. 2022

Holography, Diffractive Optics, and Applications XII

View full text Add to dashboard Cite

Due to the threshold nature of the thermochemical oxidation process, it is possible to use a non-Gaussian intensity distribution within the writing spot, for increasing of spatial resolution of direct laser writing technology. The non-Gaussian distribution was obtained by distorting the Gaussian beam with an annular diaphragm. The width of the central peak (FWHM) is 40% smaller than the width of the Gaussian spot. It has been shown that by distorting the Gaussian spot, a smaller single line width can be obtained. The effect of side lobes during multipass writing on the width of the resulting single line was studied.

show abstract