The vertical beam profile of the Innolight 2W laser was measured at eight points along the axis of the laser.
These measurements were made with the laser crystal temperature at 25.04°C and the injection current at 2.091A. z is the distance from the razor blade to the flat black face of the front of the laser.
The voltage from a photodiode was measured for the razor at a number of heights. Except for the first two points, one scan was made with the razor moving down and a second scan was made with the razor moving up. This data was fit to
y = a*erf(sqrt(2)*(x-x0)/w) + b with the following results:
| z(cm) (±0.1cm) |
w(mm) |
chi^2/ndf |
| 3.9 |
0.085 ± 0.006 |
77.09 |
| 6.4 |
0.130 ± 0.004 |
12.93 |
| 8.8 down |
0.145 ± 0.008 |
66.57 |
| 8.8 up |
0.147 ± 0.008 |
18.47 |
| 11.6 down |
0.194 ± 0.010 |
64.16 |
| 11,6 up |
0.214 ± 0.009 |
27.23 |
| 14.2 down |
0.177 ± 0.008 |
49.95 |
| 14.2 up |
0.183 ± 0.007 |
29.85 |
| 16.6 down |
0.205 ± 0.006 |
18.35 |
| 16.2 up |
0.203 ± 0.007 |
17.16 |
| 19.2 down |
0.225 ± 0.007 |
18.92 |
| 19.2 up |
0.238 ± 0.011 |
25.56 |
| 21.7 down |
0.292 ± 0.006 |
11.30 |
| 21.7 up |
0.307 ± 0.008 |
11.85 |
The values for w and its uncertainty were estimated with a weighted average between the two scans for the last six points and all eight points were fit to
w = w0*sqrt(1+(z-z0)2/zR2) with the following results:
chi^2/ndf = 17.88
w0 = (0.07 ± 0.13) mm
z0 = (-27 ± 121) mm
zR = (65 ± 93) mm
It looks like all of the data points were made in the linear region so it is hard to estimate these parameters with reasonable uncertainty. |