Hi, I'm a computer scientist w/ very little hardware experience. I've been playing with the idea of using NIRS for a brain computer interface. The basic principle is pretty simple: You have a laser diode and a detector that is 2-3 cm away from the diode. Unfortunately I have almost no experience with any of these electronic components so was wondering if I could get some guidance. I've found the lasers here: http://search.digikey.com/us/en/products/D8505I/38-1030-ND/287034 [Broken] Now I need a detector which will basically measure how much light is bounced back out of the skull. I would like to sample this at somewhere around 100-500 Hz. It is important that there be as little noise and as much precision as possible. I was looking at using a "photodetector" (is that the right part?) http://search.digikey.com/us/en/products/PNZ335/PNZ335-ND/274305 [Broken] The photodetector would be wired to a fiberoptic cable that would be placed on the scalp a few cm away from the emitter. There would probably be 4-6 of these detector/emitter pairs. A few key questions: 1) How do I couple the photodetector to the fiberoptic cable. 2) What sort of hardware would you recommend for connecting the photo detector to a computer and reading it in at ~100-500hz 3) Would it be possible to modulate the laser diode some how (i.e make it change power at a certain frequency). 4) Any general advice on how to go about building this or problems you think I might face. 5) Anyone interested in helping me build this/design this? I am a graduate student in Computer Science at Stanford and have a fair bit of machine learning code already written for analyzing the data (have already used the code to explore data from a NIRS machine we have on campus -- but that one only has a sample rate of 10hz) ... this project is mostly for fun and would love to collaborate with people interested in this stuff.