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== |