A fiber gas sensor includes a fiber core with first and second refractive index periodic modulated grating structures having different amplitude modulation profiles positioned about the fiber core. As the handle is capable of rotating in all directions, a user can clean a surface without feeling strain in his or her joints. The subsystems can include an illuminationmodulation subsystem, a tissue sampling subsystem, a data acquisition subsystem, a computing subsystem, and a calibration subsystem. A heat sink is formed in the bulk silicon layer and configured to sink heat through the bulk silicon layer, to the back surface of the wafer. The combination apparatus also includes an area for storage of extra lens cups, an area for storage of sterile cleaning solution, and a cover to keep certain areas of the cleaning solution applicator sterile while not in use.