Micro-hole drilling and cutting using femtosecond fiber laser

Abstract

Abstract. Micro-hole drilling and cutting in ambient air are presented by using a femtosecond fiber laser. At first, the micro-hole drilling was investigated in both transparent (glasses) and nontransparent (metals and tissues) materials. The shape and morphology of the holes were characterized and evaluated with optical and scanning electron microscopy. Debris-free micro-holes with good roundness and no thermal damage were demonstrated with the aspect ratio of 8∶1. Micro-hole drilling in hard and soft tissues with no crack or collateral thermal damage is also demonstrated. Then, trench micromachining and cutting were studied for different materials and the effect of the laser parameters on the trench properties was investigated. Straight and clean trench edges were obtained with no thermal damage.

Micromachining features of TiC ceramic by femtosecond pulsed laser

“…Femtosecond pulsed laser represents an alternative tool for the micromachining of ceramics due to its ultra-short laser pulses and ultra-high laser intensity [12,13]. It has the potential to provide a simple and cost-effective technique without special gas environment.…”

Dispersion variation in ring‐type erbium‐doped fiber ultrashort pulse laser with single‐wall carbon nanotube‐based tapered fiber saturable absorber

“…The exposure of the human body to radio frequency (RF) from wireless transmitter is expressed in specific absorption rate (SAR) [1][2][3][4]. The SAR is a dosimetric measure and its unit is W/kg.…”

“…The SAR is a dosimetric measure and its unit is W/kg. The peak mass-averaged SAR values for 1 g tissue allowed by the U.S. Federal Communication Commission are 1.6 W/kg in North America, and the International Commission on Non-Ionizing Radiation Protection of the European Union guidelines stipulates the limit of 2 W/kg in 10 g of tissue [2,3]. Various safety standards were also established for the RF exposure in the industrial world [3].…”

“…Various safety standards were also established for the RF exposure in the industrial world [3]. It should be noticed that the 10 g SAR at 2 W/kg is equal to the 1 g SAR at 4-6 W/kg due to the different volume of tissue used to define the SAR (larger volume tends to smooth the SAR distribution) [2]. The SAR is the absorbed power per unit volume P a (W/m 3 ) divided by the tissue/body mass density q (kg/m 3 ) as expressed by…”

Study of femtosecond laser pulse drilling of silicon

“…There is an increasing demand for high aspect ratio micro hole in different materials for micro sensors and micro heat exchangers to obtain higher efficiency (Huang et al 2014).…”