This Research Reports an Advancement in Splicing Silica Glass Fiber to Sapphire Single-Crystal Optical Fiber (SCF) using a Specialized Glass Processing Device, Including Data that Demonstrate the Thermal Stability of the Splice to 1000◦C. a Filament Heating Process Was Used to Produce a Robust Splice between the Dissimilar Fibers. a Femtosecond Laser is Used to Inscribe a Fiber Bragg Gratings Sensor into the SCF to Measure the High-Temperature Capabilities and Signal Attenuation Characteristics of the Splice Joint. the Experimental Results Demonstrate that the Proposed Splicing Method Produces a Splice Joint that is Robust, Stable, Repeatable, and Withstands Temperatures Up to 1000◦C with a Low Attenuation of 0.5 DB. the Proposed Method Allows Placement of SCF-Based Sensors in the Extreme Environments Encountered in Various Engineering Fields, Such as Nuclear, Chemical, Aviation, and Metals Manufacturing, to Enable Improvements in Process Monitoring, Product Quality, and Production Efficiency.