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We have demonstrated micromachining of bulk 3C silicon carbide (3C- SiC) wafers by employing 1028nm wavelength femtosecond laser pulses of energy less than 10 nJ directly from a femtosecond laser oscillator, thus eliminating the need for an amplified system and increasing the micromachining speed by more than four orders of magnitude.
We have investigated the ablation behaviour of single crystal SrTiO3 <100> with focus on the influence of the pulse duration at a wavelength of 248 nm. The experiments were performed with KrF-excimer lasers with pulse durations of 34 ns and 500 fs, respectively. Femtosecond-ablation turns out to be more efficient by one order of magnitude and to eliminate the known problem of cracking of SrTiO3 during laser machining with longer pulses. In addition, the cavities ablated with femtosecond pulses display a smoother surface with no indication of melting and well-defined, sharp edges. These effects can be explained by the reduced thermal shock effect on the material by using ultrashort pulses.
Compression of ultrashort laser pulses via gated multiphoton intrapulse interference phase scans
(2014)
The goal of this paper is to design a low-loss 1 x 32 Y-branch optical splitter for optical transmission systems, using two different design tools employing Beam Propagation Method. As a first step, a conventional 1 x 32 Y-branch splitter was designed and simulated in two-dimensional environment of OptiBPM photonic tool. The simulated optical properties feature high loss, high asymmetric splitting ratio and a large size of the designed structure, too. In the second step of this work we propose an optimization of the conventional splitter design leading to suppression of the asymmetric splitting ratio to one-third of its initial value and to the improvement of the losses by nearly 2 dB. In addition, 50% size reduction of the designed structure was also achieved. This length-optimized low-loss splitter was then modelled in a three-dimensional environment of RSoft photonic tool and the simulated results confirm the strong improvement of the optical properties.