Aim: To measure the optical power from led using a powermeter.
Yesterday Gautam drilled a larger hole of diameter 5mm in the box as an aperture for led (aperture angle is approximately 2*tan-1(2.5/7) = 39 deg). I repeated the measurements that I had done before (https://nodus.ligo.caltech.edu:8081/40m/13951). The measurents of optical power measured using a powermeter and the corresponding input voltages are listed below.
Input voltage (Vcc in V) |
Optical power |
0 (dark reading) |
0.8 nW |
10 |
1.05 mW |
12 |
1.15 mW |
15 |
1.47 mW |
16 |
1.56 mW |
18 |
1.81 mW |
So we are able to receive optical power close to the value (1.6mW) given in Thorlabs datasheet for LED1050E (https://www.thorlabs.com/drawings/e6da1d5608eefd5c-035CFFE5-C317-209E-7686CA23F717638B/LED1050E-SpecSheet.pdf). I hope we can proceed to BRDF measurements for CCD calibration.
Steve: did you center the LED ?
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