For the most part this week, I've been figuring out the optical system and components that we are going to include in the magnetic tweezers setup. It's been problematic so far, because we're having difficulty with the parts list from one of Professor Andresen's friends. Complicating the situation is the fact that they're in Singapore, so any communication is delayed significantly.
One of the first problems we have is determining how to focus the collimated light coming out of the objective. This light has to be focused in order to be stored on our CCD. We have a choice of either a f=100 or f=180mm lens. However, we're unsure if (and what would happen) if we include both lenses in the setup at the same time. Secondly, we need to figure out what type of LED we want as our light source. We're leaning to using Thorlabs as our main supplier for all of our opto-mechanical and optics equipment for ease. So, for the most part of this afternoon, I've been chatting with a tech-adviser from Thorlabs for help with selecting the LED and the appropriate opto-mechanical components. Right now we're leaning towards a red (625nm) LED w/ an output power of 1000mA. To collimate the LED, we'll be constructing our own collimator out of different Thorlab stuff. We'll be using an aspherical lens with AR coating in some appropriate housing to collimate the light from the LED. This housing will attach to the LED itself. Of course, the main problem now is making sure that the whole list of everything we need is complete, and get everything ordered.