Titanium Nano-Antenna for High-Power Pulsed Operation

Integration of bow-tie plasmonic nano-antennas on tapered fibers

“…However, in order to better control the fluence (energy per unit area) that reached the antennas, we have used a Q-switched laser. In fact, as demonstrated by Mironov and co-authors [15], a high fluence reaching the antenna can obliterate the antennas and a Q-switch laser can produce pulses with controlled fluence and, at the same time, allows the nano-antennas to cool down in the interval between consecutive pulses. In addition, the Q-switched laser has an emission spectrum broad enough to allow us to conduct the refractive index sensing measurements.…”

“…A nano-antenna can, for example, be directly fabricated on the optical fiber tip [11]. In this setup, however, all power guided by the fiber is solely used to drive the antennas and it can also be damaged at high fluences [12]. Moreover, an array of antennas at the end of an optical fiber can reflect light back to the laser and produce instabilities in its operation.…”

Laser Systems for Distant Monitoring of Nanopowder Combustion

“…The ignition of the combustion process was provided by 532 nm continues wave radiation of DPSS laser. According to [32], ablation and ignition should occur at a certain threshold fluence. The threshold value for 532 nm radiation was 50 MBT of continuous wave radiation focused on the sample by 9.5 cm focus lens.…”

Enhancing Weak Optical Signals Using a Plasmonic Yagi—Uda Nanoantenna Array

“…In addition to Yagi-Uda nano-antennas, other nano-antennas can lead to high directivity [9]- [12] such as a plasmonic nanowire [10], a honeycomb-like antenna structure [11] or a dipole placed close to a ring reflector [12]. Nano-antennas can be fabricated at the end of the fiber [13] or on the fiber cladding: given that nano-antennas are tiny and cannot handle high fluence [14], fabricating them on the fiber cladding allows a better control of the amount of fluence that reaches the antennas, thereby avoiding their obliteration. In addition to that, metallic structures at the end of the fiber can act as mirrors and reflect light back to the laser cavity, where it can lead to instabilities in the laser operation.…”

“…The grid sizes are chosen as x = y = z = 20 nm, which are further refined to 5 nm close to the edges of the metallic structures. The refractive index of the cladding is assumed to be 1.45, while gold is simulated as a dispersive medium with multiple resonances [14], [15]. A Gaussian source is launched at the fiber cladding to simulate light coming from the fiber, with a spot-size of 2 μm by 500 nm (vertical direction).…”