Previous EO test conclusions indicated that smaller waveguides would yield better diffraction (line spacing) in EO.

3um channel EO matched with 100um wide AO.

Results: Streak died out by end of EO. Suspected loss from too much diffraction. Still saw an AO controllable spot, but not AOEO controllable.

10um channel EO matched with 100um wide AO, reduced EO section from 4000um to 2000um.

Results: Streak went all the way to the AO section, but AO again did not work inside the EO area. Better AO control just outside of EO section than previous test.

10um channel EO with 100um wide AO, eliminating extra aluminum defining waveguide channels after the EO region to eliminate any absorption of the surface acoustic waves inside the waveguide region.

Results: 3 transducers disconnected during prism coupling process, leaving the largest EO region. New to this device: sending the streak down the center, lining up with the center of the transducer we saw AO effects. Previous devices have required the streak to be just outside the EO waveguide region for AO to function.

To do: re-wirebond the top devices and check if AO works inside EO region for all sizes. If so, removing the Al did make a difference.

10um waveguide EO with slab waveguide instead of long channels between EO and AO region.

Results: Again, only the largest device worked. This time with no subchannels the streak dispersed more in the slab waveguide. This caused a very long AO effect, not sure if that is preferable or not. However, inside the AO region this time, we got a blink!

AO RANGE

EO BLINK

Now, to optimize.

8um waveguide EO with slab waveguide but with varying distance between EO and AO regions.