ElectroHolography Laboratory

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==Third sample set: Begun 6 May, 2016==
\\
{{:probe_2_power_ratios.jpg?direct&100|}} \\
This is a layout of the apparatus that I have been using. The sample goes in a little holder that we have. It should be placed in the apparatus such that the laser shoots through the back into the grating. Then you can adjust the x, y, z and theta so that you can see the mode lines coming out of the wave guide. The mode lines that are coming out should be TE polarized. Pr
I worked out measurements of Theta = 39.02, x = 6.04, y = 0.41,\\ 
The z changes according to the different waveguides: **2.7** , 3.54, 4.23, 4.5, 5.19, **5.82** . The bold are the ones I am most confident about. 
{{:red_testing_apparatus.jpg?direct&100|}}
This next one is a picture of the light coming out through a waveguide. 
{{:probe_test_2_red_light.jpg?direct&1000|}} 
This is a different waveguide, a smaller one and you can only see the TE polarized light
{{:probe_test_2_red_polarized.jpg?direct&1000|}}
This is going to be the same test as I was going to run on sample 2. Because the design did not come out properly after the Heidelberg I am just going to rerun the fabrication process from that step. The design is therefore the same and I hope that this time the design will come out as planned. \\
The matlab parameters were:\\
Sample Dimensions:\\
x=15000um,\\
y=10000um\\ \\
Label and Alignment Parameters:\\
border = 500\\
textHeight = 500\\
markSize = 400\\
lineThick = 30\\ \\
Probe Waveguide Parameters:\\
length = 15000\\
number of probes = 5\\ \\
Probe 1 width = 1000\\
Probe 2 width = 3.333333e+02\\
Probe 3 width = 1.111111e+02\\
Probe 4 width = 3.703704e+01\\
Probe 5 width = 1.234568e+01\\
{{:probe_test2_mask_etch_noninverted_probewaveguides.jpg?direct&1000|}}
{{:probe_test2_success.jpg?direct&1000|}}
I know this says sample 2, because it is the second design but not the 2nd sample. Everything worked a lot better this time even though I do not know what I changed to make the heidelberg print correctly. As you can see, it does look a little off center as if it was just a little bit diagonal but I think that is better and I hope that it does not affect the end result. The rest of the process has gone well I believe. I may have taken off just a little bit too much aluminum in the Al etch, but unless it seriously effects the proton exchange there should not be a problem. \\
The apparatus I used to test is the one with the red laser. There are a lot of different adjustments on that setup. The settings for test probe 2 were:\\ Theta = 320.95\\ X = 12.5\\ Y = 0.41\\ Z = 4.6\\ 
The things that I am looking for are some TE polarized lines which you can see using a black and white screen in the laser room. After we had found the correct angle, I went into the Al etch to remove the remaining aluminum. To keep track of the front face, I wrote a BP along the side. If the grating is at the top, then the BP should be coming down vertically on the right side. If you look through the microscope on the same desk as the metricon, the grating should be towards you and as you go up the left side then you should read BP just fine because of the 180 degree reflection in the microscope. Coming out of the Al etch there appeared a couple big defects at the same place as my BP lettering. I do not know why these appeared, it could have been that the diamond pen didn't react well under hot acid. Also the acid felt a little more hot than usual and could have caused a cracking.



==Second sample set: Begin 5 May, 2016==
I am creating a new sample because we found that the waveguides from the previous sample were a little too small. We looked around for them but were not able to find them so they could guide light. This time, we are going to use waveguides that are a little bit bigger so that we can find them easier. We also may postpone the final aluminum etching step until we have found the waveguides and measured their respective angles so we can find them again once the aluminum is gone. \\
The matlab parameters were:\\
Sample Deminsions:\\
x=15000um,\\
y=10000um\\ \\
Label and Alignment Parameters:\\
border = 500\\
textHeight = 500\\
markSize = 400\\
lineThick = 30\\ \\
Probe Waveguide Parameters:\\
length = 15000\\
number of probes = 5\\ \\
Probe 1 width = 1000\\
Probe 2 width = 3.333333e+02\\
Probe 3 width = 1.111111e+02\\
Probe 4 width = 3.703704e+01\\
Probe 5 width = 1.234568e+01\\
{{:probe_test2_mask_etch_noninverted_probewaveguides.jpg?direct&1000|}}
As I performed the aluminum etching, I found a slight problem with my sample. Somehow the settings on the Heidelberg must have been incorrect or different because my sample came out incorrectly. The design printed correctly, it just printed it in the wrong place. Because the design was off center, most of the design is missing and a large portion of the sample was left blank. \\ I assume that the next thing I should do is probably print the design again on a different sample and start again. I will probably just use Al etch to clear away the aluminum and then put it through the E-beam with the next batch so that I can use it again in the future. \\
{{:probe_test2_heidelbergfail.jpg?direct&1000|}}


==First sample set: Begin 3 May, 2016== 

Using a matlab script named basic_Probe I created a test probe. This probe contained a few different rectangles of varying sizes so that we can see how the light reacts to different sized channels. \\
We took it through the normal process of prepping with S1805::EBR::1:1. Then we sent it through the heidelberg and through the polishing process. \\

The matlab parameters were \\
Sample Dimensions:\\
x=15000um,\\
y=10000um\\
\\
Label and Alignment Parameters:\\
border = 500\\
textHeight = 500\\
markSize = 400\\
lineThick = 30\\

Probe Waveguide Parameters:\\
length = 15000\\
number of probes = 5\\
\\
Probe 1 width = 120\\
Probe 2 width = 80\\
Probe 3 width = 5.333333e+01\\
Probe 4 width = 3.555556e+01\\
Probe 5 width = 2.370370e+01\\ \\

{{:probe_test1_mask_etch_noninverted_probewaveguides.jpg?direct&1000|}}
{{:probe_test1_picwithal.jpg?direct&1000|}}
{{:basic_probe_1_metricon.png?direct&1000|}}
ElectroHolography Laboratory

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