THE APPLICATION OF FIBEROPTIC MULTIFUNCTION SENSING SYSTEM MEASURING TEMPERATURE AND PRESSURE DURING THE CURING OF FIBERGLASS/EPOXY COMPOSITE STRUCTURES IS DESCRIBED. THE SYSTEM EMPLOYS INTERFEROMETRIC PRINCIPLES TO MEASURE TEMPERATURE, PRESSURE, REFRACTIVE INDEX OF LIQUIDS, AND OTHER PHYSICAL PARAMETERS. FIBEROPTIC PRESSURE AND TEMPERATURE SENSORS HAVE BEEN EMPLOYED IN MONITORING COMPOSITES PULTRUSION AND MOLDING. THE SYSTEM IS IDEALLY SUITED FOR MONITORING A VARIETY OF COMPOSITE CURING PROCESSES BECAUSE OF THE SENSOR'S MICROMINIATURE SIZE, TOLERANCE OF MODERATELY HIGH TEMPERATURES, NON-METALLIC CONSTRUCTION, AND INHERENT IMMUNITY TO ELECTROMAGNETIC AND RADIO FREQUENCY SIGNALS.