Fluid gel for fiber optic gap

A system for an ablation catheter, the system comprising:

• a catheter including:
• a shaft including a distal end,
• a tip coupled to the distal end of the shaft, the tip including a displacement feature between a proximal portion and a distal portion of the tip, the distal portion configured to move with respect to the proximal portion based on the displacement feature,
• a first optical fiber coupled to the proximal portion,
• a second optical fiber coupled to the distal portion and optically aligned with the first optical fiber, wherein the second optical fiber is positioned at a distance from the first optical fiber and is configured to move with respect to the first optical fiber according to a displacement of the distal portion of the tip, and
• a fluid located between the first optical fiber and the second optical fiber;
• an optical emitter configured to transmit a transmission signal through the first optical fiber and into the second optical fiber;
• an optical sensor configured to receive a reflection signal based on the reflection of the transmission signal off of the second optical fiber;
• and
• a microprocessor communicatively coupled to the optical sensor, the microprocessor configured to calculate a force applied to the distal portion of the tip based on the reflection signal.