Role of lens to sample distance during laser-induced damage in zinc targets

Abstract

We report on the experimental investigation of nanosecond laser-induced Zn target damages versus the lens to sample distance (LTSD). The varieties of typical surface profiles associated with the evolutions of laser ignited plasma expansion were described in detail. According to the observed results, an established transient state of modified structure within an early phase of single-pulse laser ablation should play a critical role in the steps of final damage and plasma expanding. Due to the transient state, re-enhance absorption of laser energy will occur immediately in this case. On the other hand, it is deduced that the rise curves of transient absorption coefficient should obey an exponential growth, as the LTSD increasing from 103 mm to focal length ∼ 111 mm.

Direct synthesis of size-tailored bimetallic Ag/Au nano-spheres and nano-chains with controllable compositions by laser ablation of silver plate in HAuCl4 solution

“…We have found that the modied spot can lead to an enhanced absorption of the following laser energy. 18,19 This is unfavorable for the synthesis of homogeneous bimetallic nanoparticles. A Q-switched Nd-YAG (yttrium aluminum garnet) laser (Quanta Ray, Spectra Physics) beam operating at a wavelength of 1064 nm with a pulse duration of about 6 ns and 10 Hz repetition rate was focused onto the Ag target surface.…”

Repeatability improvement of laser-induced breakdown spectroscopy using an auto-focus system

“…where μ w is weighted arithmetic mean, W i shows intensity values and X i shows positions of pixels [15].…”

“…In this range, the laser beam concentrates on a small area on the sample surface. LTSD factor, can affect the emission intensities, plasma characteristics such as plasma temperature and shape, mass of ablated material and the degree of damaging [13][14][15]. All above mentioned parameters have their maximum value at around focal point [16].…”

Effect of lens focusing distance on laser-induced silicon plasmas at different sample temperatures

“…Chen et al reported experimentally on an investigation of nanosecond laser-induced Zn target damages and the distance from the lens to the sample. With the distance close to the focal point (103 mm to 111 mm), the damage area decreased obviously and the ablation depth increased gradually [25]. Zhang et al reported the effects of the distance from the lens to the sample surface on the laser induced plasma expansion dynamics [26].…”