Controlled+temperature+jump

__Controlled temperature jump__

In order for the laser to be successfully used as a lab instrument directed towards our studies we have to be able to control the amount that we increase the temperature of the sample. It is not enough to to be able to shoot the laser at the sample and have the temperature increase. The goal is to be able to take the laser, fire it at the sample, and be able to make it increase a certain temperature every time (we were aiming for about 20 degrees celcius, but currently is is around 13 degrees from when we tested it with a thermocouple). One thing that is crucial to getting the same amount of temperature change is allignment. Everytime the laser is turned on the temperature increases the temperature of the sample about the same amount, however the the temperature where the laser hits is greater than its surroundings. There is a temperature gradient on the surface of the gold. So the farther you are away from the 1mm laser spot the lower the temperature is in comparision to where the laser is hitting the surface. This means that the tip has to be within this 1mm diameter laser spot in order for the temperature change to be consistent every time.

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