...
3) A third option is to use a Fabry lens, where the input pupil is imaged onto the optical fiber surface. See http://www.hposoft.com/IAPPP/PEPManual/ManualP6.html for an example of this.
A link to at least one example of Linux code for Ocean Optics is here, could likely be used with Raspberry Pi system:
https://code.google.com/p/linuxmeasurement/