ElectroHolography Laboratory

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======D_Wafer======

This is the lithium niobate wafer the allows testing of 91MHz designed tandsducers that are narrow and wide, long and short.

====Test 1 - Angle Dependence====

This test was done using the smallest 91MHz trandsucer in the bottom right corner. The yellow light was found to have minimal impact and so was left on. The red laser was used at 6V with a 28dBm signal coming from the amplifier (11.8 V to the amp). 94MHz was found to produce the maximum light deflection and 85MHz produced none.

^  Angle  ^  85MHz  ^  94MHz  ^  ▲W  ^  % Increase  ^
|  11°  |  33.3µW  |  38.7µW  |  5.4µW  |  16.22%  |
|  21°  |  16.5µW  |  18.8µW  |  2.3µW  |  13.94%  |
|  31°  |  13.8µW  |  15.9µW  |  2.1µW  |  15.22%  |
|  40°  |  13.0µW  |  14.3µW  |  1.3µW  |  10.00%  |
|  51°  |  6.7µW  |  7.2µW  |  1.1µW  |  7.46%  |

{{:samples:d:d_wafer_test_1._angel_dependence.png?500|}}

Note: I had to change position of the wand between each angle and so inaccuracies were added. I believe that that is what accounts for the lager jump at 11. **It appears that the smallest footprint (shallowest angle) provides the best interaction**. 
====Test 2 - Spot Size====

This test was done using the smallest 91MHz trandsucer in the bottom right corner. With the wafer at 21° off of normal. The yellow light was found to have minimal impact and so was left on. The red laser was used at 6V with a 28dBm signal coming from the amplifier (11.8 V to the amp). 94MHz was found to produce the maximum light deflection and 85MHz produced none.

^  Distance from Lens  ^  85MHz  ^  94MHz  ^  ▲W  ^  % Increase  ^
|  80mm  |  18.5µW  |  21.5µW  |  3µW  |  16.22%  |
|  85mm  |  26.7µW  |  30.2µW  |  3.5µW  |  13.11%  |
|  87mm  |  22.1µW  |  25.9µW  |  3.8µW  |  17.19%  |
|  90mm  |  21.4µW  |  25.1µW  |  3.7µW  |  17.29%  |
|  95mm  |  22.6µW  |  25.7µW  |  3.1µW  |  13.72%  |
|  100mm  |  24.9µW  |  27.2µW  |  2.3µW  |  9.24%  |
|  105mm  |  25.1µW  |  26.4µW  |  1.3µW  |  5.18%  |
|  110mm  |  26.7µW  |  27.4µW  |  0.7µW  |  2.62%  |

{{:samples:d:d_wafer_test_2._spot_size.png?500|}}

Note: These required much less motion and should therefore be more accurate. At 110mm I could not see the change with my eye by knowing the pattern I placed the wand where it should go and ran the test anyway. **It seems that tighter spots have a better interaction**. 

====Test 3 - Distance to Transducer====

This test was done using the smallest 91MHz trandsucer in the bottom right corner. With the wafer at 21° off of normal. The yellow light was found to have minimal impact and so was left on. The red laser was used at 6V with a 28dBm signal coming from the amplifier (11.8 V to the amp). 94MHz was found to produce the maximum light deflection and 85MHz produced none.

^  Distance from Transducer  ^  85MHz  ^  94MHz  ^  ▲W  ^  % Increase  ^
|  0.3mm  |  32.3µW  |  37.4µW  |  5.1µW  |  15.79%  |
|  0.8mm  |  33.8µW  |  38.1µW  |  4.3µW  |  12.72%  |
|  1.3mm  |  66.5µW  |  71.3µW  |  4.8µW  |  7.22%  |
|  1.8mm  |  60.5µW  |  63.2µW  |  2.7µW  |  4.46%  |
|  2.3mm  |  60.8µW  |  63.4µW  |  2.6µW  |  4.28%  |
|  2.8mm  |  22.8µW  |  24.6µW  |  1.4µW  |  7.89%  |
|  3.3mm  |  22.2µW  |  24.0µW  |  1.8µW  |  8.11%  |
|  3.8mm  |  18.7µW  |  20.2µW  |  1.5µW  |  8.02%  |

{{:samples:d:d_wafer_test_3._distance_from_transducer.png?500|}}

**Closer to the transducer as expected is better**.

====Test 4 - Transducer Length====

This test was done using the smallest 91MHz trandsucer in the bottom right corner and the two other with the same width but x2 and x3 lenght. With the wafer at 21° off of normal. The measurements were made in the dark. The red laser was used at 6V with a 28dBm signal coming from the amplifier (11.8 V to the amp). 94MHz was found to produce the maximum light deflection and 85MHz produced none.

^  Transducer  ^  85MHz  ^  94MHz  ^  ▲W  ^  % Increase  ^
|  x1  |  9.20µW  |  14.1µW  |  4.9µW  |  53.26%  |
|  x2  |  13.9µW  |  15.4µW  |  1.5µW  |  10.79%  |
|  x3  |  23.5µW  |  26.5µW  |  3.0µW  |  12.77%  |


This is not what was expected. It probably is caused by differences in independence matching.
ElectroHolography Laboratory

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