High throughput, fast detection and characterization of geological materials have become important challenge for future lunar robotic rover exploration and planetary missions. To allow for sample characterization on the moon and Mars, rover missions need to decide what samples to acquire for further onboard analysis. An in situ non-destructive detection technique is highly desirable remote sensing tool for many future missions. We propose to develop a fiber Raman spectrometer for field detecting of geological materials. Recent advances in fiber lasers, fiber optic probes and Raman analysis techniques make the development of such a key component feasible. We expect our innovative design for fiber Raman spectrometer will significantly improve the flexibility of remote Raman collection, so that the field spectrometer's overall performance would be intact and extremely flexible for the field detection.