Photonic Associates Torsion Pendula


During the development of the microthruster, we developed, calibrated and used three different torsion pendula. In the research phase, when we were interested in testing the pulsed laser impulse response of small samples of prospective target materials, some of the most sensitive torsion pendula ever created were used.


In the development phase, when it was necessary to suspend the entire microthruster from the device to measure its thrust, a much sturdier device was developed.


The table below shows the response and sensitivity of each version:









High sensitivity device

7 micro-N-s/radian

100 pico-N-s

2 micro-N-s

Laser beam /mirror

Medium sensitivity device

36 micro-N-s/radian

5 nano-N-s

2 micro-N-s

Laser beam/mirror

High capacity (1)

40 milli-N/radian

2 micro-N

40 milli-N

Laser beam/mirror

High capacity (2)

1.3 milli-N/radian

25 nano-N

100 micro-N

Laser beam/ interferometric display







Click the links for further details on the high sensitivity device and and the high capacity device.