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Femtosecond laser processing by using patterned vector optical fields.

Lou K, Qian SX, Ren ZC, Tu C, Li Y, Wang HT - Sci Rep (2013)

Bottom Line: The PVOFs can be flexibly engineered due to the diversity of individual vector optical fields in spatial arrangement and distribution of states of polarization, and it is easily created with the aid of a spatial light modulator.The focused PVOFs will certainly result in various interference patterns, which are then used to fabricate multi-microholes with various patterns on silicon.The present approach can be expanded to fabricate three-dimensional microstructures based on two-photon polymerization.

View Article: PubMed Central - PubMed

Affiliation: MOE Key Laboratory of Weak Light Nonlinear Photonics and School of Physics, Nankai University, Tianjin 300071, China.

ABSTRACT
We present and demonstrate an approach for femtosecond laser processing by using patterned vector optical fields (PVOFs) composed of multiple individual vector optical fields. The PVOFs can be flexibly engineered due to the diversity of individual vector optical fields in spatial arrangement and distribution of states of polarization, and it is easily created with the aid of a spatial light modulator. The focused PVOFs will certainly result in various interference patterns, which are then used to fabricate multi-microholes with various patterns on silicon. The present approach can be expanded to fabricate three-dimensional microstructures based on two-photon polymerization.

No MeSH data available.


Related in: MedlinePlus

Fabrication of multi-microholes by the fs PVOFs composed of four individual linearly-polarized scalar fields with m = 0 and a = 1.0 mm.(a) and (b) are the two PVOFs composed of four individual linearly-polarized scalar fields, which arrange a square, where the arrows show the SoP configurations. (c) shows the simulated Airy spot of the focused individual field. (d) is the simulated interference pattern with a tetragonal lattice of four individual fields. (e) indicates the simulated pattern of the focused PVOF, which contains four bright spots. (c)–(e) have a dimension of 60 × 60 μm2. (f) is the SEM image of the multi-microholes fabricated by 50 pulses at a fluence of about 6.9 J/cm2.
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f1: Fabrication of multi-microholes by the fs PVOFs composed of four individual linearly-polarized scalar fields with m = 0 and a = 1.0 mm.(a) and (b) are the two PVOFs composed of four individual linearly-polarized scalar fields, which arrange a square, where the arrows show the SoP configurations. (c) shows the simulated Airy spot of the focused individual field. (d) is the simulated interference pattern with a tetragonal lattice of four individual fields. (e) indicates the simulated pattern of the focused PVOF, which contains four bright spots. (c)–(e) have a dimension of 60 × 60 μm2. (f) is the SEM image of the multi-microholes fabricated by 50 pulses at a fluence of about 6.9 J/cm2.

Mentions: We now experimentally investigate the fabrication of multi-microholes on silicon surface, by using the focused fs PVOFs. In experiments, we focus on the cases only when all the individual vector optical fields forming the PVOF are the AV-LP-VFs with the same topological charge m and the same radius of a. We first explore a special PVOF composed of four individual linearly-polarized scalar fields (corresponding to the m = 0 AV-PL-VF). The experimentally generated two kinds of PVOFs composed of four individual linearly-polarized scalar fields with a = 1.0 mm. The four individual fields form a square and locate at (x10, y10) = (1.56, 1.56) mm, (x20, y20) = (−1.56, 1.56) mm, (x30, y30) = (−1.56, −1.56) mm, and (x40, y40) = (1.56, −1.56) mm, respectively, as shown in Figs. 1a and 1b. The two individual fields in the first and third quadrants have the same initial phases ϕ10 = ϕ30 = 0 in Fig. 1a (ϕ10 = ϕ30 = π/2 in Fig. 1b), while the two in the second and fourth quadrants also have the same initial phases ϕ20 = ϕ40 = π in Fig. 1a (ϕ20 = ϕ40 = 3π/2 in Fig. 1b), respectively. The arrows in the individual fields in Figs. 1a and 1b show the corresponding SoPs. The simulation results reveal a fact that for any one of the individual fields (Figs. 1a and 1b), its focal field has the same intensity pattern of an Airy spot (Fig. 1c), as the above theoretical predication, implying that the initial phase determining SoP has no influence on the focal intensity pattern. The simulated interference pattern described by the interference factor P exhibits a tetragonal lattice (Fig. 1d). As shown in Eq. (6b), the interference pattern depends on both positions and SoPs of the four individual fields. The simulated intensity pattern of the focused PVOF is composed of four bright spots exhibiting a square (Fig. 1e), which originates from the splitting of the Airy spot of the focused individual field due to the modulation of the interference factor of the four fields. At a fluence of about 6.9 J/cm2, four microholes are punched on the silicon surface by 50 pulses (Fig. 1f), which has the same pattern as the focused PVOF (Fig. 1e).


Femtosecond laser processing by using patterned vector optical fields.

Lou K, Qian SX, Ren ZC, Tu C, Li Y, Wang HT - Sci Rep (2013)

Fabrication of multi-microholes by the fs PVOFs composed of four individual linearly-polarized scalar fields with m = 0 and a = 1.0 mm.(a) and (b) are the two PVOFs composed of four individual linearly-polarized scalar fields, which arrange a square, where the arrows show the SoP configurations. (c) shows the simulated Airy spot of the focused individual field. (d) is the simulated interference pattern with a tetragonal lattice of four individual fields. (e) indicates the simulated pattern of the focused PVOF, which contains four bright spots. (c)–(e) have a dimension of 60 × 60 μm2. (f) is the SEM image of the multi-microholes fabricated by 50 pulses at a fluence of about 6.9 J/cm2.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3722566&req=5

f1: Fabrication of multi-microholes by the fs PVOFs composed of four individual linearly-polarized scalar fields with m = 0 and a = 1.0 mm.(a) and (b) are the two PVOFs composed of four individual linearly-polarized scalar fields, which arrange a square, where the arrows show the SoP configurations. (c) shows the simulated Airy spot of the focused individual field. (d) is the simulated interference pattern with a tetragonal lattice of four individual fields. (e) indicates the simulated pattern of the focused PVOF, which contains four bright spots. (c)–(e) have a dimension of 60 × 60 μm2. (f) is the SEM image of the multi-microholes fabricated by 50 pulses at a fluence of about 6.9 J/cm2.
Mentions: We now experimentally investigate the fabrication of multi-microholes on silicon surface, by using the focused fs PVOFs. In experiments, we focus on the cases only when all the individual vector optical fields forming the PVOF are the AV-LP-VFs with the same topological charge m and the same radius of a. We first explore a special PVOF composed of four individual linearly-polarized scalar fields (corresponding to the m = 0 AV-PL-VF). The experimentally generated two kinds of PVOFs composed of four individual linearly-polarized scalar fields with a = 1.0 mm. The four individual fields form a square and locate at (x10, y10) = (1.56, 1.56) mm, (x20, y20) = (−1.56, 1.56) mm, (x30, y30) = (−1.56, −1.56) mm, and (x40, y40) = (1.56, −1.56) mm, respectively, as shown in Figs. 1a and 1b. The two individual fields in the first and third quadrants have the same initial phases ϕ10 = ϕ30 = 0 in Fig. 1a (ϕ10 = ϕ30 = π/2 in Fig. 1b), while the two in the second and fourth quadrants also have the same initial phases ϕ20 = ϕ40 = π in Fig. 1a (ϕ20 = ϕ40 = 3π/2 in Fig. 1b), respectively. The arrows in the individual fields in Figs. 1a and 1b show the corresponding SoPs. The simulation results reveal a fact that for any one of the individual fields (Figs. 1a and 1b), its focal field has the same intensity pattern of an Airy spot (Fig. 1c), as the above theoretical predication, implying that the initial phase determining SoP has no influence on the focal intensity pattern. The simulated interference pattern described by the interference factor P exhibits a tetragonal lattice (Fig. 1d). As shown in Eq. (6b), the interference pattern depends on both positions and SoPs of the four individual fields. The simulated intensity pattern of the focused PVOF is composed of four bright spots exhibiting a square (Fig. 1e), which originates from the splitting of the Airy spot of the focused individual field due to the modulation of the interference factor of the four fields. At a fluence of about 6.9 J/cm2, four microholes are punched on the silicon surface by 50 pulses (Fig. 1f), which has the same pattern as the focused PVOF (Fig. 1e).

Bottom Line: The PVOFs can be flexibly engineered due to the diversity of individual vector optical fields in spatial arrangement and distribution of states of polarization, and it is easily created with the aid of a spatial light modulator.The focused PVOFs will certainly result in various interference patterns, which are then used to fabricate multi-microholes with various patterns on silicon.The present approach can be expanded to fabricate three-dimensional microstructures based on two-photon polymerization.

View Article: PubMed Central - PubMed

Affiliation: MOE Key Laboratory of Weak Light Nonlinear Photonics and School of Physics, Nankai University, Tianjin 300071, China.

ABSTRACT
We present and demonstrate an approach for femtosecond laser processing by using patterned vector optical fields (PVOFs) composed of multiple individual vector optical fields. The PVOFs can be flexibly engineered due to the diversity of individual vector optical fields in spatial arrangement and distribution of states of polarization, and it is easily created with the aid of a spatial light modulator. The focused PVOFs will certainly result in various interference patterns, which are then used to fabricate multi-microholes with various patterns on silicon. The present approach can be expanded to fabricate three-dimensional microstructures based on two-photon polymerization.

No MeSH data available.


Related in: MedlinePlus