Femtosecond laser filamentation in condensed media with Bessel beams

Dota, Krithika; Pathak, Abhishek; Dharmadhikari, J. A.; Mathur, D.; Dharmadhikari, A. K.

doi:10.1103/physreva.86.023808

Cited by 23 publications

(15 citation statements)

References 52 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These discrete damage traces are attributed to the beating between the Bessel beam and the axial radiation. Regular focusing-refocusing events of similar nature were observed in [9] in barium fluoride crystal in the filaments, excited by axicon-formed femtosecond Bessel pulses.Several papers examined femtosecond filamentation in solid birefringent media, which are of great interest as structural materials for femtosecond lasers (see, e.g., [10][11][12][13][14][15]). A simplified case of the filament excitation only by ordinary or extraordinary ray was addressed in most of these studies.…”

mentioning

confidence: 77%

mentioning

confidence: 77%

“…Longitudinal periodicity of different nature has been observed earlier in femtosecond filaments in isotropic media [5][6][7][8][9] in tight focusing conditions (NA > 0.3). In most cases, such a periodicity is associated with the…”

Section: Introductionmentioning

confidence: 85%

See 2 more Smart Citations

Periodic femtosecond filamentation in birefringent media

et al. 2015

View full text Add to dashboard Cite

phenomenon of multiple refocusing [5]. Up to three peaks of on-axis luminescence intensity were observed when the authors of [6] focused a femtosecond laser pulse into an isotropic fused silica sample with a high-NA objective. Multiple irregular refocusing of tightly focused femtosecond laser pulse, with the distance between the refocusing maxima varying from 20 to 40 μm, was observed inside fused silica in [7]. The phenomenon was associated with the focal spot extension along the propagation axis due to the spherical aberration, induced by the air-sample interface. It was shown in [8] that filaments generated by pulsed Bessel beams form discrete equidistant damage spots in borosilicate glass. These discrete damage traces are attributed to the beating between the Bessel beam and the axial radiation. Regular focusing-refocusing events of similar nature were observed in [9] in barium fluoride crystal in the filaments, excited by axicon-formed femtosecond Bessel pulses.Several papers examined femtosecond filamentation in solid birefringent media, which are of great interest as structural materials for femtosecond lasers (see, e.g., [10][11][12][13][14][15]). A simplified case of the filament excitation only by ordinary or extraordinary ray was addressed in most of these studies.In this paper, we report on the observation of longitudinally periodic filamentation of femtosecond laser radiation in positive (n o < n e ; crystalline quartz) and negative (n o > n e ; sapphire) birefringent crystalline media in loose focusing conditions (NA = 0.02). We focus on little studied and unattainable in isotropic material peculiarities of the filamentation process, which are caused by spatial and temporal overlap of ordinary (o) and extraordinary (e) pulses inside the crystal. It is in this case the specificity of femtosecond filamentation in birefringent medium is shown in full. AbstractWe report on the experimental observation of periodic modulation of the axial luminescence intensity along the femtosecond filament track in sapphire and crystal quartz. The physical reason for the modulation is a cyclic transformation of the polarization state of the light pulse traveling in birefringent medium, caused by the phase raid between the ordinary and extraordinary rays, and different cross sections of multiphoton absorption for linear and circular polarizations.

show abstract

mentioning

confidence: 77%

mentioning

confidence: 77%

See 1 more Smart Citation

Periodic femtosecond filamentation in birefringent media

et al. 2015

View full text Add to dashboard Cite

show abstract

“…In that regard, SC generation was studied using femtosecond Bessel beams with various parameters: cone angle, central spot size, energy content, particular intensity variation along the propagation axis and length of the Bessel zone. Self-focusing of ultrashort-pulsed Bessel beams was investigated in various nonlinear media, such as water [298], methanol [299], sapphire [30] and BaF 2 [300,301], and demonstrated that the SC radiation appears on the propagation axis. However, due to energy distribution between the central spot and surrounding rings, Bessel beams are very resistant to self-focusing, and 10-100 times higher incident energy is required to induce filamentation and achieve an appreciable spectral broadening.…”

Section: Other Developmentsmentioning

confidence: 99%

Ultrafast supercontinuum generation in bulk condensed media

Dubietis¹,

Tamošauskas²,

Šuminas³

et al. 2017

Lith. J. Phys.

172

View full text Add to dashboard Cite

Nonlinear propagation of intense femtosecond laser pulses in bulk transparent media leads to a specific propagation regime, termed femtosecond filamentation, which in turn produces dramatic spectral broadening, or superbroadening, termed supercontinuum generation. Femtosecond supercontinuum generation in transparent solids represents a compact, efficient and alignment-insensitive technique for generation of coherent broadband radiation at various parts of the optical spectrum, which finds numerous applications in diverse fields of modern ultrafast science. During recent years, this research field has reached a high level of maturity, both in understanding of the underlying physics and in achievement of exciting practical results. In this paper we overview the state-of-the-art femtosecond supercontinuum generation in various transparent solid-state media, ranging from wide-bandgap dielectrics to semiconductor materials and in various parts of the optical spectrum, from the ultraviolet to the mid-infrared spectral range. A particular emphasis is given to the most recent experimental developments: multioctave supercontinuum generation with pumping in the mid-infrared spectral range, spectral control, power and energy scaling of broadband radiation and the development of simple, flexible and robust pulse compression techniques, which deliver few optical cycle pulses and which could be readily implemented in a variety of modern ultrafast laser systems.

show abstract

“…However, in the unsteady Bessel filamentation regime, refocusing cycles enable periodic illumination of the sample. This has been described theoretically [5] and observed experimentally [8] and is in contrast to normal Gaussian beam based filamentation. Our present experiments lie in the unsteady Bessel filamentation regime.…”

mentioning

confidence: 84%

Axicon-based writing of waveguides in BK7 glass

et al. 2013

View full text Add to dashboard Cite

We report on the direct writing of waveguide structures using an axicon lens to focus a 40 fs laser pulse within BK7 glass. The written structures are characterized for waveguiding action: waveguiding action for 635 and 1550 nm light and propagation loss as low as 0.19 dB/cm is measured. Loss values decrease with laser exposure time for incident energy of 300 μJ, indicating enhancement of index contrast. At higher energies, a reverse trend is obtained: higher loss values are obtained as index contrast degrades with an increase in exposure time.

show abstract

Femtosecond laser filamentation in condensed media with Bessel beams

Cited by 23 publications

References 52 publications

Periodic femtosecond filamentation in birefringent media

Periodic femtosecond filamentation in birefringent media

Ultrafast supercontinuum generation in bulk condensed media

Axicon-based writing of waveguides in BK7 glass

Contact Info

Product

Resources

About