For these tests, I am going to try dilute Proton Exchange. It takes a lot longer but I think that this process will minimize loss and thus help to get the results we are seeking.

All of the masks work the same way. You can decide which size of waveguide you would like and the matlab file is parameterizable so you can change those widths if you wish. All of the waveguide masks use the same AO file once they have been taken through the process and are ready for the AO step after Proton Exchange of the Waveguides.
The problem with the previous design was that we had a loss. When a device finally worked and was able to align, we were not able to see well the deflection caused by the AOM. This design is an attempt to rectify that situation and see both which size of waveguide is the best and which size of transducer responds to that waveguide. I have put the transducers closer to the waveguides to take care of loss and have made them shorter also for loss.

At the testing stage Kamran and I were concerned about the quality of the waveguides and modes. I took another sample from the same wafer that had not yet had fabricated transducers on it into the metricon and received this data. I think this is sufficient to believe that the waveguides and modes are properly working.

This test is a similar design except that the waveguides are already places on the device and so I will not be writing the EO devices onto it to get the waveguides. These samples need to be cleaned and placed in proton exchange and then written on the Heidelberg with the design. Then after Al etch they should be ready for testing. This design includes a lot more waveguides and so it will be easier to find the modes. It should be tested with prism coupling because there is not grating on these samples.
The copper piece and the AO transducers need to be at different heights with the AO below because the light will pop out and scan down from the device.
The waveguides have a width of 80-100 um. Chris designed them with a file called thingy.dxf last summer.

I have decided to forestall these tests because we are a little bit confused about what the grating is doing. We are unsure if our design is working and so we will wait on that a little bit. This design is a remake of AO Test 1. I am now fabricating it with a masked process which entails taking the EO section all the way through proton exchange and then prepping again and rewriting in the heidelberg to achieve the desired AO transducers. This also has one key difference that the width of my devices is a lot smaller, they are 100 um in width.
You can tell the top because when the grating is on the left of the device, there is more space at the top than the bottom.

This is a design from Stephen that I am going to fabricate and test. This design uses a mask system and can be found under the file label of SPD. It is an EO device that we will use as waveguides without the liftoff process. Then we will put AO transducers on it to test how well it works. This is a picture with the grating on the left, EO in the middle and AO on the right.

I learned on May 16th that my current design would not work as I had previously thought. AO devices rely on the physical crystal structure which is shattered when proton exchange happens. For that reason, you cannot just put waveguides and AO devices on the same device and expect it to work the way you want it to. I learned that I needed to use a mask system where I would fabricate the waveguides and EO device with a big mask over where the AO device will go and then I need to process the AO device with a mask over my completed EO device. That presents a bigger stumbling block than I had foreseen. I talked to Stephen and he said that he had a completed AO design that I could fabricate and test so I will do that first before I come up with my own masks and such. That will help me to learn the AO process and be able to understand what I need to make for my AO devices. My concern though is that the designs that we currently have are not very time effective. They could take a large portion of the Heidelberg time and do not compile in Matlab very well and take upwards of an hour or so just to compile and make the files. On the left we have some EO design which we are not currently using as EO but using more as waveguides. The right has some AO transducers which is our main test. Mostly we want to see how the two will interact when we place them on the same chip. The grating will be left of the EO devices.

The concept for this project is wanting to work on AO devices in an effort to move forward to have an AO/EO device by the end of the summer.