High efficiency GHz laser processing with long bursts

Abstract

Bursts of GHz repetition rate pulses can significantly increase the ablation efficiency of femtosecond laser material processing.. Ablation by GHz repetition rate bursts of femtosecond pulses is a multi-step process, consisting of a first thermal incubation phase, followed by a highly efficient ablation phase. GHz ablation therefore combines thermal and non-thermal ablation mechanisms. With an optimal choice of the burst duration, the ablation efficiency can be highly enhanced. Long bursts, comprising tens to hundreds of pulses, are required to take full advantage of the increase in ablation efficiency.

Enhancement of Broadband Reverse Saturable Absorption of Red/Black Phosphorus Heterojunction

“…where Imχ 3 is the imaginary part of the third order optical susceptibility, c is the ve The NLO performance is characterized by the optical setup in Figure 5. The laser and optical instrument parameters can be found in Section 3.4 on characterization.…”

“…where Imχ (3) is the imaginary part of the third order optical susceptibility, c is the velocity of light, n 0 is the linear refraction, and ω is the angular frequency of light. The nonlinear absorption coefficients and the imaginary parts of third-order NLO susceptibilities are calculated through fitted values.…”

“…Since the invention of the first ruby laser in 1960, laser technology has made rapid progress [ 1 ]. In recent years, many laser technologies have emerged and brought great convenience to humanity, such as laser ranging [ 2 ], laser processing [ 3 ], laser display [ 4 ], and laser sensing [ 5 ]. However, high-energy damage to the human eyes or optical system also occurs at the same time [ 6 , 7 ].…”

Ablation rate assessment of GHz femtosecond laser in burst mode through fast numerical simulation

“…In this way, the temporal sequence of the energy distribution onto the material can be flexibly modified. Audouard et al [6] have tested in an experimental campaign different pulse repetition rates with a burst rate settled at 100 kHz. Their findings showed that by increasing the fluence of the burst and the burst duration, the ablation depth increases.…”