581
edits
Changes
Jump to navigation
Jump to search
Diamond Radiator Thinning Using an Excimer Laser (view source)
Revision as of 21:15, 15 December 2016
, 21:15, 15 December 2016→Ablation Rate
Line 71:
Line 71:
|-
|-
|}
|}
+
+The ablation rate was calculated using the model shown below in Eq. 1
+and accounts for the overlap between neighboring laser pulses as well as the
+12
+fluctuations in laser energy (elaser) from row to row.
+R(elaser) = U(y) ∗ δx ∗ δy
+V0
+(1)
+U(y) is the number of microns removed (in µm) from the diamond surface
+after ablation at a particular y coordinate as measured from the Zygo interferometer,
+δx and δy are the distances between neighboring pulses (both
+10µm) and V0 was a normalization parameter representing the depth cut in
+diamond from a single laser pulse. The data collected from Figure 9a was
+used in Eq. 1 and plotted as a function of the laser energy shown in Figure
+9b. The fit of Figure 9 was made using a second order polynomial and is
+shown below in Eq. 2.
+R(elaser) = 245.347x
+2 + 5.440x − 2.390 (2)
+During the ablation process the average laser energy was measured for
+each completed row and the corresponding ablation rate was calculated using
+Eq. 2. The ablation rate calculated from the last completed row was used
+to determine its overlap with the next row of laser pulses. The overlap was
+adjusted by weighting a standard step size made by the y-translation stage
+(y-step) by the ratio of the measured ablation rate with a desired rate of
+ablation as shown in Eq. 2.
+delta-y = R(measured)
+R(desired)
+∗ y-step (3)
+Stacking laser pulses on top of eachother increases the amount of diamond
+material removed within the region of overlap. This method was used to
+account for laser energy fluctuations while differentially ablating diamond to
+within ±0.5µm surface variation.
==Ablation Rate==
==Ablation Rate==