Photometric Testing
Rather than paying another company to phometrically test Agira optical films, we opted to do this in-house with a 3B laser. This process is very tedious, however, so it was necessary to use a motorized setup that could take many readings across a range of precise angles in a matter of seconds.
For this I used a sample holder which allowed a motor to be place on top. The motor swung an arm with a photodiode set at the height of the laser. For every orientation of the sample, we could have data for nearly 360 degrees of reflected or refracted light.
Goniometer Component Design
Making some of the components needed to integrate the motor saved time. I decided to 3D print a motor mount and sensor attachment. Having the motor's axis be the same as the sensor's rotation allowed for a very simple setup.
The first version used a motor that was far too bulky and heavy. The sample size to be used in this design was also unnecessarily large.
Sample/motor mount, version 1 (left), version 2 (right)
Sample/motor mount version 3 printed in onyx for strength
At the base of the sample/motor mount is an optical bench fixed goniometer. Mounted to this is my 3-D printed sample mount with a pocket for a stepper motor above the sample window. On the stepper motor's shaft is an adapter that holds a length of 8020 profile. The photo diode is mounted on this profile.
Stepper motor in 3D printed sample stand.
Eveything was setup on an optical bench for easy fixturing.
The swinging sensor arm
