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Message ID: 13951     Entry time: Tue Jun 12 19:27:25 2018
 Author: pooja Type: Update Category: Cameras Subject: CCD calibration

Today I made the led (1050nm) circuit inside a box as given in my previous elog. Steve drilled a 1mm hole in the box as an aperture for led light.

Resistance (R) used = 665 $\Omega$.

We connected a power supply and IR has been detected using the card.

Later we changed the input voltage and measured the optical power using a powermeter.

 Input voltage (Vcc in V) Optical power 0 (dark reading) 60 nW 15 68 $\mu$W 18 82.5 $\mu$W 20 92 $\mu$W

Since the optical power values are very less, we may need to drill a larger hole.

Now the hole is approximately 7mm from led, therefore aperture angle is approximately 2*tan-1(0.5/7) = 8deg. From radiometric curve given in the datasheet of LED1050E, most of the power is within 20 deg. So a hole of size 2* tan(10) *7 = 2.5mm may be required.

I have also attached a photo of the led beam spot on the IR detection card.

 Attachment 1: IMG_20180612_163831.jpg  1.226 MB  Uploaded Tue Jun 12 20:50:02 2018
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