230
G. Feng et al.
7.3.5 Average Diameter of the Micro-hole Arrays
with Different Fluence
The number of accumulated laser pulses for drilling each hole was set to 2000
to achieve sufficient repeatability. The dependence of the average diameter of the
micro-holes on the fused silica sheet and aluminum coated-fused silica sheet versus
the fluence of femtosecond laser is shown in Fig. 7.19.
As shown in Fig. 7.19, the average diameter of the micro-hole arrays on the
fused silica sheet and aluminum coated-fused silica sheet increased with increasing
femtosecond laser fluence. When the femtosecond laser fluence was between 0.1 and
40 J/cm
2 , the average diameter of the micro-holes on the fused silica sheet increased
rapidly with the laser fluence. With the fluence higher than 40 J/cm
2 , the average
diameter seemed to almost reach a maximum and remain unchanged. However, the
average diameter of the micro-holes on the fused silica sheet was a little larger than
that on the aluminum coated-fused silica sheet.
The morphologies of micro-holes fabricated at different laser fluences for coated
and uncoated silica sheets are shown in Fig. 7.20. For coated silica, although the
fluence of the laser pulse is changed, the crack and collateral damage around the hole
are almost invisible due to the aluminum coating; for uncoated silica, the decrease of
the fluence of the laser pulse may decrease the crack and collateral damage around
the holes, but cannot make them disappear. Thus, it is a good choice to improve the
quality of the femtosecond laser processing by coating with film on the surface of
sample.
Fig. 7.19 Dependence of the average diameter of the micro-hole arrays on the fused silica sheet
and aluminum coated-fused silica sheet versus the fluence of femtosecond laser
G. Feng et al.
7.3.5 Average Diameter of the Micro-hole Arrays
with Different Fluence
The number of accumulated laser pulses for drilling each hole was set to 2000
to achieve sufficient repeatability. The dependence of the average diameter of the
micro-holes on the fused silica sheet and aluminum coated-fused silica sheet versus
the fluence of femtosecond laser is shown in Fig. 7.19.
As shown in Fig. 7.19, the average diameter of the micro-hole arrays on the
fused silica sheet and aluminum coated-fused silica sheet increased with increasing
femtosecond laser fluence. When the femtosecond laser fluence was between 0.1 and
40 J/cm
2 , the average diameter of the micro-holes on the fused silica sheet increased
rapidly with the laser fluence. With the fluence higher than 40 J/cm
2 , the average
diameter seemed to almost reach a maximum and remain unchanged. However, the
average diameter of the micro-holes on the fused silica sheet was a little larger than
that on the aluminum coated-fused silica sheet.
The morphologies of micro-holes fabricated at different laser fluences for coated
and uncoated silica sheets are shown in Fig. 7.20. For coated silica, although the
fluence of the laser pulse is changed, the crack and collateral damage around the hole
are almost invisible due to the aluminum coating; for uncoated silica, the decrease of
the fluence of the laser pulse may decrease the crack and collateral damage around
the holes, but cannot make them disappear. Thus, it is a good choice to improve the
quality of the femtosecond laser processing by coating with film on the surface of
sample.
Fig. 7.19 Dependence of the average diameter of the micro-hole arrays on the fused silica sheet
and aluminum coated-fused silica sheet versus the fluence of femtosecond laser